A Taliban spokesman said the group "believes the martyrdom of Sheikh Osama bin Laden will give a new impetus to the current jihad against the invaders." Bin Laden lived for years in Afghanistan and is thought to have plotted the September 11, 2001, attacks on the United States from there.

One of bin Laden's wives, Amal Ahmed Abdulfattah, told Pakistani interrogators the al Qaeda leader had been living for five years in the compound where he was killed, a Pakistani security official told Reuters.

The disclosure appeared sure to heighten US suspicions that Pakistani authorities had been either grossly incompetent or playing a double game in the hunt for bin Laden and the two countries' supposed partnership against violent Islamists.

Pakistani security forces took 15 or 16 people into custody from the Abbottabad compound after US forces removed bin Laden's body, said the security official. They included bin Laden's three wives and several children.

In Washington, a US official said US intelligence had established on-the-ground surveillance in Abbottabad in advance of the raid.

US officials also said among materials found at bin Laden's hide-out was evidence indicating al Qaeda at one point considered attacking the US rail system on the 10th anniversary of the September 11 attacks later this year.

Officials said evidence analyzed so far indicated bin Laden was still involved in directing al Qaeda's activities, even though he had largely avoided the public spotlight for years.

The fact that bin Laden was found in a garrison town -- his compound was not far from a military academy -- has embarrassed Pakistan and the covert raid has angered its military.

Pressure is building in the US Congress to suspend or at least review US aid to Pakistan.

Video footage

The Pakistan army, for its part, threatened on Thursday to halt counterterrorism cooperation with the United States if it conducted any more similar raids.

It was unclear if such attacks included drone strikes the US military conducts regularly against militants along Pakistan's border with Afghanistan.

Pakistani security officials have charged that US troops, after landing by helicopter, shot the unarmed al Qaeda leader in cold blood rather than in a firefight, as US officials first suggested.

Amid differing accounts this week of how much hostile fire the SEALs encountered in the compound, one Pakistani security official said on Friday that US forces should release video footage he said they "must have" of the operation.

UN human rights investigators called on the United States to disclose the full facts "to allow an assessment in terms of international human rights law standards."

The Pakistani military also said on Thursday it had decided to reduce the US military presence in the country.

In Washington, Pentagon spokesman Colonel David Lapan said the Defense Department had not received notice from Islamabad about any decision to change the size of the US military contingent in Pakistan. He said there were a little under 300 US military personnel in Pakistan, many of them trainers.

US Defense Secretary Robert Gates said the relationship was "complex" but pointed to Pakistan's effort against the Taliban and al Qaeda in its own tribal areas and the use of its territory as a US supply route.

"At the same time, there's no question they hedge their bets," said Gates, fielding questions from service members at an Air Force base in North Carolina. "Their view is that we have abandoned them four times in the last 45 years. And they're not sure we're going to stay in the region."

"So we just have to keep working at it, on both sides," he added.