No proof Pakistanis knew Osama bin Laden location: US

There is no evidence Pakistani officials knew Osama bin Laden was living at a compound deep inside the country, but the United States is not ruling out the possibility, President Barack Obama's counterterrorism adviser said on Tuesday.

The death of the al-Qaeda leader in Monday's US raid on his compound in Abbott, a military garrison town 38 miles (62 km) from the capital Islamabad, has led some US lawmakers to demand a review of US aid to nuclear-armed Pakistan.

"They (Pakistani officials) are expressing as great a surprise as we had when we first learned about this compound, so there is no indication at this point that the people we have talked to were aware of this, but we need to dig deeper into this," White House counterterrorism chief John Brennan said in an interview with National Public Radio.

In an opinion piece in the Washington Post, Pakistan's President Asif Ali Zardari said bin Laden "was not anywhere we had anticipated he would be" but he did not answer accusations his security services should have known of the hide-out.

When asked whether officials in Pakistan's military might have known about bin Laden's presence in the compound, Brennan said it was possible.

"I think it would be premature to rule out the possibility that there were some individuals inside of Pakistan, including within the official Pakistani establishment, who might have been aware of this, but we're not accusing anybody at this point."

Brennan said it appeared that bin Laden had lived for the past five to six years in the compound in Abbott, the site of an important Pakistani military academy.

Bin Laden was living in neighboring Afghanistan at the time of the al-Qaeda September. 11 attacks on the United States and when a subsequent US-led invasion helped topple the Taliban government.

"Well I think the latest information is that he was in this compound for the past five or six years and he had virtually no interaction with others outside that compound. But yet he seemed to be very active inside the compound," Brennan said on the CBS Early Show program.

"And we know that he had released videos and Audis. We know that he was in contact with some senior al Qaeda officials," Brennan added.

"So what we're trying to do now is to understand what he has been involved in over the past several years, exploit whatever information we were able to get at the compound and take that information and continue our efforts to destroy al Qaeda," Brennan added.

He also said the United States was continuing to pursue Ayman al-Zawahiri, al-Qaeda's chief organizer and the possible successor to bin Laden, and that it was believed he was living in Afghanistan or Pakistan.

"I'm not going to say what country he is in," Brennan told NPR.

Brennan also said the United States was considering whether to release photographs and video taken during the raid but has not yet made a decision.

"We want to make sure that we're able to do it in a thoughtful manner. We also want to anticipate what the reaction might be on the part of al Qaeda or others to the release of certain information so that we can take the appropriate steps beforehand," Brennan told CNN.

"Any other material, whether it be photos or videos or whatever else - we are looking at it and we'll make the appropriate decisions," Brennan said.

Asked about any computers, documents and other material seized at the compound, Brennan said the material was being reviewed by US authorities.

"What we're most interested in is seeing if we can get any insight into any terrorist plot that might be underway so that we can take the measures to stop any type of attack planning. Secondly, we're trying to look and see whether or not there are leads to other individuals within the organization or insights into their (al-Qaeda) capabilities," Brennan said.

He said the United States was eager to learn from the material about the circumstances of bin Laden's residence in Abbott.