Pakistan has evidence that al-Qaeda’s second in command was in a house hit by a U.S. drone strike in the country's northwest tribal region, but it is unclear whether he was killed, intelligence officials said Tuesday, June 5, AP reported.

U.S. officials have said they were targeting Abu Yahya al-Libi in Monday's strike in Khassu Khel village in the North Waziristan tribal area and were "optimistic" he was among those killed. They spoke on condition of anonymity because of the classified nature of the drone program.

Militants and residents in the area told Pakistani agents that al-Libi was in the house when it was hit, said intelligence officials, also speaking on condition of anonymity because they were not authorized to talk to the media.

A vehicle used by al-Libi was destroyed during the strike, said one of the officials. Agents intercepted a militant phone call indicating an Arab was killed in the attack, but it is unclear if they were talking about al-Libi, who was born in Libya, said the official.

A local Taliban chief said al-Libi's guard and driver were killed in the strike, but the al-Qaeda commander was not there. Al-Libi did survive a previous strike, said the Taliban chief, speaking on condition of anonymity for fear of being targeted by the Pakistani army.

If al-Libi is confirmed killed, he would be the latest in the dozen-plus senior commanders removed in the clandestine U.S. war against al-Qaeda since Navy SEALs killed Osama bin Laden last year.

The White House maintains a list of terrorist targets to be killed or captured, compiled by the military and the CIA and ultimately approved by the president.

The U.S. has stepped up drone strikes in Pakistan recently, carrying out seven in less than two weeks. The flurry follows a relative lull driven by tensions between Washington and Islamabad over American airstrikes last year that killed 24 Pakistani soldiers.