Covert U.S. soldiers have participated in attacks against Al Qaeda hideouts in Pakistan and are searching for pockets of militants along the border region, The Washington Post reported.

U.S. troops based on the Afghanistan side of the mountainous frontier have been attacked several times a week over the last month and have been in several firefights with Al Qaeda militants, the Post reported in Thursday's edition, citing unidentified U.S. military officials.

The Americans have suffered some casualties, though no American has been killed, the Post said.

U.S. forces have found only small pockets of Al Qaeda forces since the end of a weeklong ground and air assault in the Shah-e-Kot valley south of Kabul, the Afghan capital. Since then, the military has been quiet on whether U.S. forces are operating in Pakistan, where many Al Qaeda fighters are believed to have fled.

Pentagon officials could not be reached for comment late Wednesday night.

In the Afghan regions, members of the U.S. Special Forces and Delta Force have been deliberately exposing themselves to attack to draw out the small pockets of Al Qaeda and Taliban fighters believed to be hiding in the border area, the Post said, again citing military officials.

U.S. officials earlier Wednesday had said the Bush administration was considering sending U.S. advisers to work with Pakistani troops in the pursuit of Al Qaeda and Taliban fighters in Pakistan.

A senior administration official said it was his understanding that an agreement may already have been reached but another official said the two countries had not yet reached that point.

Asked about a New York Times report that an agreement has been reached, Pentagon spokeswoman Victoria Clarke declined comment except to say that Pakistan has been very helpful in the war on terrorism.

"The cooperation continues to get better and better all the time," she said.

At issue is a strategy to deal with hundreds of Al Qaeda and Taliban militants who are believed to have taken refuge in a lawless region near the Afghan border.

One official said Pakistan was reluctant to acknowledge contacts with the United States about joint military cooperation in tracking down terrorists out of concern for public opinion.

He noted that Pakistani authorities themselves traditionally have been reluctant to engage in law enforcement activities in the area, preferring to leave policing to local tribal authorities.

Pentagon officials have indicated for months that they think it is unlikely that Pakistan would agree to joint military operations in pursuit of suspected terrorists inside Pakistan, and some have said they believe it would be unwise because of a likely political backlash.

The approach taken by Gen. Tommy Franks, the U.S. commander of the war in Afghanistan, has been to coordinate and consult with the Pakistani military in pursuing Al Qaeda fugitives, but to let the Pakistani authorities carry out the operations.

The main U.S. role has been in providing intelligence and law enforcement support, rather than direct military involvement.

The joint Pakistani-U.S. raids that led to the capture of suspected terrorist Abu Zubaydah are thought to be models for future counterterrorism operations in Pakistan. They relied on U.S. civilian, rather than military, authorities.

Abu Zubaydah is alleged to have been one of Usama bin Laden's top planners of terrorist operations, with knowledge of Al Qaeda plots and operational cells. He was captured in Pakistan on March 28 and is recovering from three gunshot wounds he received in the raid.