Top US defense officials have said there is no evidence Pakistan's leadership was aware Osama bin Laden was in their country before he was killed in a US military raid at the beginning of the month. They have cautioned against punitive action over the incident.

Bin Laden's killing earlier this month in a compound in Abbottabad, a garrison town near the Pakistani capital, deeply embarrassed Pakistan's military and spy agencies, and led to calls by members of the US Congress for a tougher approach toward the country.

Many US lawmakers have voiced their dismay that the al Qaeda leader was found in a military town not far from Pakistan's capital and have urged the Obama administration to review security aid to the country.

This week, a group of Democratic senators wrote in a letter to Gates and US Secretary of State Hillary Clinton that finding bin Laden in a Pakistani garrison town indicates "a lack of commitment by the Pakistani military to aggressive cooperation with the United States."

No evidence

But Gates has warned that Obama's administration should not simply point the finger: "It's hard to go to them with an accusation when we have no proof that anybody knew."

"I have seen no evidence at all that the senior leadership knew. In fact I've seen some evidence to the contrary," US Defense Secretary Robert Gates told a Pentagon press conference on Wednesday - the first since bin Laden was killed.

However, he did say it was his "supposition that somebody had to know, but we have no ideas who and no proof and no evidence."

"I think we have to proceed with some caution," he added.

An 'opportunity'

The Pentagon chief also said that the aftermath of the raid presented a potential "opportunity," with Pakistan pledging to take more action.

"The Pakistanis, over the last couple of weeks, have expressed the view that they are willing to go after some of these people and that we should not repeat the bin Laden operation,” he said, adding that they had said "they will undertake this themselves."

This view was corroborated by the chairman of the US Joint Chiefs of Staff, Admiral Mike Mullen, who pointed out that General Ashfaq Pervez Kayani, Pakistan's army chief, had promised to go after the leaders of the Haqqani network, one of the insurgent groups blamed for launching attacks on US forces in neighboring Afghanistan.

"It is their desire now to do this themselves. And I think they certainly understand the importance of it," Mullen said. "I think we need to give them some time and space to work on some of the internal challenges that came out of this."

Mullen also cautioned against cutting off aid to Pakistan. "I think the region continues to be critical and our relationship continues to be critical," he said, adding that it would have a "significantly negative outcome if the relationship got broken."

Author: Sherpem Sherpa (Reuters, AFP, AP)
Editor: Anne Thomas