WASHINGTON - U.S. military and intelligence officials say there has been an increase in recent months in the number of foreign fighters who have traveled to Pakistan's tribal areas to join with militants there.
The flow may reflect a change that is making Pakistan, not Iraq, the preferred destination for some Sunni extremists from the Middle East, North Africa and Central Asia who are seeking to take up arms against the West, these officials say.
The American officials say the influx, which could be in the dozens but also could be higher, shows a further strengthening of the position of the forces of al-Qaida in the tribal areas, increasingly seen as an important base of support for the Taliban, whose forces in Afghanistan have become more aggressive in their campaign against American-led troops.
According to the American officials, many of the fighters making their way to the tribal areas are Uzbeks, North Africans and Arabs from Persian Gulf states.
U.S. intelligence officials say that some jihadist Web sites have been encouraging foreign militants to go to Pakistan and Afghanistan, which is considered a "winning fight," compared with the insurgency in Iraq, which has suffered sharp setbacks in recent months.
The number of foreign fighters entering Iraq has dropped to fewer than 40 a month from as many as 110 a month a year ago, a military spokesman in Baghdad said yesterday.
"The sanctuary situation in Pakistan's tribal areas and NorthWest Frontier Province is more, rather than less, troublesome than before," Gen. David D. McKiernan, the new NATO commander in Afghanistan, said in a telephone interview.
"The porous border has allowed insurgent militant groups a greater freedom of movement across that border, as well as a greater freedom to re-supply, to allow leadership to sustain stronger sanctuaries, and to provide fighters across that border."
The suicide bombing at the gates of the Indian Embassy in Kabul on Monday underscored the increasing fears of American and Afghan officials that Taliban insurgents working with Pakistani intelligence operatives might have used the bombing to pursue Pakistan's long power struggle with India.
Al-Qaida and other militant groups have used redoubts in Pakistan's rugged mountains as havens for the past several years. But especially since the new Pakistani government sharply curtailed security operations in the tribal areas in March and began negotiating with tribal leaders to rein in the militants, the number of foreign fighters entering the tribal areas has increased.