U.S. officials watched with growing concern today as reports suggested Pakistan was massing troops to the India border.
Such a move raises double-barreled worries: A possible confrontation between two nuclear powers and a shift by the Pakistani military away from battling the Taliban along its western Afghan edge.
U.S. intelligence and military officials were still trying to determine what Troop Formations are on the move, and, what Pakistan's intent may be.
Officials spoke on condition of anonymity to discuss intelligence matters.
Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, was in Pakistan twice this month, and as many as seven times in the past year. In recent meetings with senior Pakistani leaders he has urged restraint and encouraged both sides to find ways to work together.
One senior military official said today that the U.S. is monitoring the issue, but still could confirm assertions from Pakistani intelligence officials that some troops were on the move, heading to the Indian border.
A key concern for U.S. officials is that some of those troops may have been stationed along the volatile Afghan border, and were being diverted to the Indian side.
Defense Secretary Robert Gates and Mullen, who have both been in the region in recent weeks, have expressed the hope that Pakistan would stay focused on fighting militants in its mountainous northwestern Federally Administered Tribal Areas, or FATA.
The Pakistan Army's 14th Division is being redeployed to the towns of Kasur and Sialkot, close to the Indian border.
Analysts said the redeployment is likely meant as a warning to India not to launch missile strikes against militant targets on its territory. It is not likely an indication that the two countries are about to descend into war, analysts said.
"They should concentrate on the real issue: how to fight against terrorists and how to fight against and bring to book the perpetrators of [the] Mumbai terrorist attack," said Indian Foreign Minister Pranab Mukherjee.
Indian Prime Minister Manmohan Singh met with the chiefs of the army, navy and air force to discuss "the prevailing security situation," according to an official statement.

India is warning its citizens that it would be unsafe to go to Pakistan amid heightened tension.
Pakistan has begun moving thousands of troops away from the Afghan border toward India.
Pakistan has moved Major Formations of the XVI Corps (Nagrota Corps) to the Line of Control (which divides Pakistani and Indian portions of Kashmir).
Pakistan Army had moved its 10th Division to Lahore.
Infantry out of South Waziristan on the move.
The 3rd Armoured Brigade is heading towards Jhelum.
Warplanes flying over major cities.
Pakistan canceled leave for members of its armed forces Friday, beefing up its military strength in case of conflict with India over the deadly Mumbai attacks, a senior military official said.
The military remains on alert, but it has not moved additional troops to the Indian border, said the official, speaking on condition of anonymity because he was not authorized to talk to the media.
In response, India said it had not canceled any time off for its military. "People are taking leave, no problem," said Indian Defense Ministry spokesman Sitanshu Kar. "We have an optimum number, which is always maintained."
Pakistan accused Indian fighter jets of violating its airspace on two separate occasions more than a week ago, raising the possibility of conflict. But Pakistani officials subsequently played down the incidents, saying the violations, which India denied altogether, were likely accidental.
Pakistani fighter jets have flown over several of the country's major cities in recent days after the alleged airspace violations.
Pakistan and India have fought three wars since their independence from Britain in 1947, but the stakes are even higher now that both countries have nuclear weapons.
Hoax call put Pakistan on high alert South Asian regional tensions mounted last week after nuclear-armed Pakistan entered a state of “high alert” after receiving a phone call, now believed to be a hoax, from India’s foreign minister Pranab Mukherjee to Pakistan’s president Asif Ali Zardari the day that terrorist attacks on Mumbai concluded.
The caller allegedly threatened to attack Pakistan if measures were not taken to track down militants associated with the Mumbai terrorist strikes.
On Saturday, Pakistan’s Dawn newspaper reported on the incident: ”Whether it was mere mischief or a sinister move by someone in the Indian external affairs ministry, or the call came from within Pakistan, remains unclear, and is still a matter of investigation. But several political, diplomatic and security sources have confirmed to Dawn that for nearly 24 hours over the weekend the incident continued to send jitters across the world. To some world leaders the probability of an accidental war appeared very high.”
Senior Pakistani government officials confirmed the report and said the matter was under investigation, which involves efforts to trace the origin of the phone call and how it was directed to Mr Zardari.
One senior Pakistani official said Indian officials have denied that the call ever originated from Mr Mukherjee, raising the possibility that the call was a hoax. However, the Pakistani official insisted that the calling number was traced back to Mr Mukherjee’s office in New Delhi.
”We are looking at two possibilities right now. Either it was somebody from the Indian foreign ministry who used the foreign minister’s number to pull a prank or some very sophisticated technology was used to fabricate the calling number” said the official who spoke to the Financial Times on condition of anonymity.
Reporting on the reaction to the phone call, DAWN wrote; ”Intense diplomatic efforts that started late on Friday went on throughout the following day. During this period phone calls were made from Islamabad to some of the top officials and diplomats in Washington, including Condoleezza Rice, and the US Secretary of State called Mr Mukherjee and others in India in a night-long effort to understand what might have gone wrong, and to persuade the two sides to bring down the temperature.”
A senior western diplomat commenting on the report said, the incident prompted Mr Zardari to call Condoleezza Rice, US Secretary of State, to convey Pakistan’s anxiety over worsening security conditions.
Ms Rice then called Mr Mukherjee to inquire about the incident during which Mr Mukherjee categorically denied making the phone call in the first place. The western diplomat also revealed that before Ms Rice’s phone call to Mr Mukherjee, the unknown caller allegedly using the Indian foreign minister’s phone from his office, also called the US secretary of state, but was not put through to speak to her.
”Could this incident have caused a war between India and Pakistan? That is the big fear of an accidental situation coming together” said the western diplomat. ”It seems that standard procedures should have been followed in Pakistan such as someone taking down the Indian telephone number and then returning the call. That obviously did not happen, in what seemed at the time like a building up crisis situation”.
The recent Islamic terrorist carnage in India reminds everyone that India has been one the major victims of terrorism of late. Last year, Indian suffered over a thousand dead from terrorist attacks.
Over 2,000 died in 2006.
While Islamic terrorism, as in Mumbai, was a major source of deaths, it was not the only one.
The major source of Islamic terrorism in India is the Pakistani backed campaign to drive Indians, particularly non-Moslem Indians, out of the disputed, by India and Pakistan, province of Kashmir (actually Jammu-Kashmir, as the lower portion of the state, Jammu, is largely Hindu.) Kashmir, on the other side of a mountain range from Jammu, is largely Moslem, and Pakistan believes all of Kashmir (Pakistan invaded and seized northern Kashmir in the late 1940s) should be theirs.
Twenty years ago, Pakistan decided that terrorism was the only practical way to get Kashmir back. India was more powerful militarily, and had beaten Pakistan in every war between them. The terrorist groups, that have bases and training camps in Pakistani Kashmir, not only send terrorists across the border into Indian Kashmir, but have also been responsible for about two-thirds of the deaths, from Islamic terrorism, in the rest of India.
It was apparently Kashmir based terrorists who carried out the recent Mumbai atrocities.
There are several separate terrorist groups operating in Kashmir. These include; Lashkar-e-Taiba (apparently the organizers of the recent Mumbai murders), Jaish-e-Muhammad, Harakat ul-Jihad-I-Islami and Harakat ul-Mujahedeen (the last two formerly operated in Afghanistan against the Russians during the 1980s).
There have been several thousand Islamic terrorists active in Kashmir (on both sides of the border) since the late 1980s. The numbers are kept down by the deaths of most terrorists who get into Indian Kashmir.
The Pakistani based terrorists has also caused the growth of similar, but much smaller, groups inside India (which has 150 million Moslems). The Kashmir terrorism campaign has largely failed, and the number of active terrorists there has been dwindling over the past few years.
This has apparently played a part it carrying out attacks elsewhere in India. Only some parts of the Pakistani government back these terrorists, as most Pakistanis realize that too much Pakistani based Islamic terrorism inside India could trigger a major war with India. Since both nations now have nuclear weapons, this could get very ugly. The Islamic terrorists don't care, as they are on a Mission From God, and whatever happens is God's Will.
Tribal separatists in northeast India are another major source of terrorist deaths. The northeastern tribal territories only became part of India when the British colonial government departed in 1947. The tribes resented this, as well as the growing flood of migrants from other parts of India. The terrorism was directed largely at these immigrants. There used to be over 5,000 active and armed separatists, but counter-terror operations, and an amnesty program, have reduced the number to less than a thousand. Many of the separatists have devolved into criminal gangs and bandits.
The third source of terrorism is in eastern India, where communist (Maoist) rebels seek to establish a communist dictatorship, in order to resolve the social and economic inequities in the region. There are 5-10,000 armed Maoists out in the countryside, where they battle counter-terrorism forces and locals who violently disagree with the Maoists goals and methods.
India uses local police, a special force (165,000 members of the Central Reserve Police Force), the army, and several intelligence agencies to battle their terrorism problems.
The Foreign Ministry has also been useful because of its efforts to get other nations to recognize these terrorist organizations as "international terrorists", and thus subject to sanctions and prosecution overseas. This has caused Pakistan increasing problems. The "Kashmir belongs to Pakistan" cause is very popular inside Pakistan, making it difficult for Pakistan to crack down on Pakistani terrorists that carry out operations inside India, and sometimes elsewhere in the world as well.
The backlash from the Mumbai atrocities, and Islamic terrorist attacks on the Pakistani government is putting more pressure on Pakistan to crush its domestic Islamic radical groups.
This is particularly true with the Taliban in Pakistan. This group is just the most recent manifestation of violent Islamic conservatism in Pakistan's tribal areas. Pakistan has always tried to compromise with domestic terrorist groups, but the recent Islamic violence in Pakistan, Afghanistan and India is forcing Pakistan to confront Islamic terrorists, and deal with the problem once and for all. That won't be easy, as a large minority of Pakistanis support the Islamic militants.
News on the Bombay attacks is breaking fast on Twitter with hundreds of people using the site to update others with first-hand accounts of the carnage.
The website has a stream of comments on the attacks which is being updated by the second, often by eye-witnesses and people in the city. Although the chatter cannot be verified immediately and often reflects the chaos on the streets, it is becoming the fastest source of information for those seeking unfiltered news from the scene.

In the past hour, people using Twitter reported that bombings and attacks were continuing, but none of these could be confirmed. Others gave details on different locations in which hostages were being held.
And this morning, Twitter users said that Indian authorities was asking users to stop updating the site for security reasons:
One person wrote: “Police reckon tweeters giving away strategic info to terrorists via Twitter”.
Many pointed to reports that that the situation had led to clashes between Indian forces and militants in the disputed border region of Kashmir. Some messages gave the names of suspected terrorists. None of the information could be confirmed at this stage.
Twitter is a micro-blogging service, where people can send short messages of up to 140 characters to friends using text messages or over the internet.
Others have used the site to post contact details of relevant emergency services for those caught up in the attack. There were appeals for Twitter users to post “I’m fine” messages so it could be relayed onto family and friends.
Many sent messages of support to the Indian authorities and Bombay’s citizens.
One user said: “please give all respect and due to all those cops and army people who are risking their lives 4 us”. Other Bombay residents showed anger that the situation was continuing: “sadly NO ONE seems to be in charge. what are they all WAITING for 18 hours later ?”