Hussein al-Yemeni -- a top al-Qaeda planner appears to have been killed by a U.S. drone strike in Pakistan last week, U.S. officials said on Wednesday.

Washington believes the al-Qaida leader helped organize last December's deadly suicide bombing at a CIA base in Afghanistan was killed, as media reported.

"We have indications that Hussein al-Yemeni -- an important al-Qaeda planner and facilitator based in the tribal areas of Pakistan -- was killed last week," a U.S. counterterrorism official said. "He's thought to have played a key role in the attack on December 30th at Khost."

It is reported that al-Yemeni was in his late 20s or early 30s and was a conduit in Pakistan for funds, messages, and recruiting, but that he specialized in suicide operations. Moreover, al-Yemeni had established contact with groups ranging from al-Qaida in the Arabian Peninsula to Afghan and Pakistani Taliban militant groups.

CIA Director Leon Panetta, in an interview with the Washington Post published on its website on Wednesday, said attacks against al-Qaeda in Pakistan's tribal regions appear to have driven Osama bin Laden and other leaders deeper into hiding, leaving the organization incapable of planning sophisticated operations.

"It's pretty clear from all the intelligence we are getting that they are having a very difficult time putting together any kind of command and control, that they are scrambling. And that we really do have them on the run," Panetta said.

The CIA has stepped up the intensity of unmanned aerial drone attacks and intelligence-gathering operations in Pakistan since the Dec. 30 bombing in the eastern Afghan province of Khost.