Published: May 03, 2011 6:37 PM EDT
Updated: May 03, 2011 8:54 AM EDT

ABBOTTABAD, Pakistan (AP) - Pakistan's leader denied suggestions that his country's security forces sheltered Osama bin Laden as Britain demanded Tuesday that Islamabad answer for how the al-Qaida chief lived undetected for six years in a large house in a garrison town close to the capital.

But in a nod to the complexities of dealing with a nuclear-armed, unstable country that is crucial to success in the war in neighboring Afghanistan, British Prime Minister David Cameron said having "a massive row" with Islamabad over the issue would not be in Britain's interest.

A day after U.S. commandos killed bin Laden, reporters were allowed within the 15-foot, barbed-wire-topped walls of the compound for the first time. But the doors of the house were sealed shut and police were in no mood to open them.

Local residents showed off small parts of what appeared to be a U.S. helicopter that Washington said malfunctioned and was disabled by the American strike team as they retreated. A small servant's room outside the perimeter showed signs of violent entry and had been briskly searched, clothes and bedding tossed to the ground. Its wall clock was on the floor, the time stuck at 2:20, when the U.S. team would have been on the ground in the early hours of Monday.

Asif Ali Zardari's comments, in a Washington Post opinion piece Monday, were Pakistan's first formal response to suspicions raised by U.S. officials and others. Those suspicions could further sour relations between Islamabad and its Western backers at a key point in the war in Afghanistan.

Bin Laden was killed close to a military academy in the bustling northwestern town of Abbottabad, not in the remote Afghan border region where intelligence assessments had assumed he had been holed up. That was quickly taken as a sign of possible collusion with the country's powerful security establishment, which Western officials have long regarded with a measure of suspicion despite several notable al-Qaida arrests in the country since 2001.

"Some in the U.S. press have suggested that Pakistan lacked vitality in its pursuit of terrorism, or worse yet that we were disingenuous and actually protected the terrorists we claimed to be pursuing. Such baseless speculation may make exciting cable news, but it doesn't reflect fact," Zardari wrote.

Ties between the two nominal allies were already strained amid U.S. accusations that the Pakistanis are supporting militants in Afghanistan and Pakistani anger over American drone attacks and spy activity on its soil. They came to head in late January after a CIA contractor shot and killed two Pakistan's, in what Washington said was self-defense.

U.S. Senate Armed Services Committee Chairman Carl Levin said Pakistan's intelligence and army have "got a lot of explaining to do," given that bin Laden was holed up in such a large house with surrounding buildings, the fact that its residents took the unusual step of burning their garbage and avoiding any trash collection.

"It's hard to imagine that the military or police did not have any ideas what was going on inside of that," Levin said.

Cameron, who has also made supporting Pakistan a major foreign policy commitment, echoed those concerns.

"Those are questions we have to ask, those are questions we will want answered and we will be asking that question of everyone in Pakistan and the Pakistani government," Cameron told BBC radio before acknowledging the West's limited leverage against Islamabad.

"We could go down the route of having some massive argument, massive row with Pakistan, but I assess our relationship with Pakistan and it is my very clear view that it is in out interests to work with the government and people of Pakistan to combat terrorism, combat extremism and help development in that country."

Suspicions were also aired in many Pakistan's media and on the street Tuesday.

"That house was obviously a suspicious one," said Jahangir Khan, who was buying a newspaper in Abbottabad. "Either it was a complete failure of our intelligence agencies or they were involved in this affair."

U.S. officials have said that Pakistani officials were not told about the early morning helicopter raid until the strike team had killed bin Laden had returned to Afghanistan from where they took off from, citing security reasons.

Many Pakistanis were surprised at how this was possible, especially when initial reports stated that the choppers took off from a Pakistani air base. Some were angry that the country's sovereignty had been violated - an especially sensitive issue given the unpopularity of America here.

Zardari said it "was not a joint operation" - the kind of which has been conducted in the past against lesser terror suspects in Pakistan - but that Pakistani cooperation, in a general sense, had helped lead them to bin Laden.

"A decade of cooperation and partnership between the United States and Pakistan led up to the elimination of Osama bin Laden as a continuing threat to the civilized world," he said.

President Barack Obama also said the country's anti-terror alliance had helped in the run-up to the operation, but did not thank Pakistan when he announced the death of bin Laden.

The death has raised fears of revenge attacks, both in Pakistan - which has seen hundreds of suicide attacks by al-Qaida and its allies since 2007 - and internationally. The U.S Embassy said its missions in Pakistan would remain closed to the public until further notice.

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