A senior U.S. official says al-Qaida's chief of operations in Pakistan has been killed in the country's northwest tribal region.

The official, who did not want to be named, said Thursday that Abu Hafs al-Shahri was killed earlier this week, but did not give details.

Pakistani security officials said a U.S. drone strike killed at least three people on Sunday. It was unclear whether that attack was the one which killed Shahri.

The announcement comes just weeks after U.S. officials said al-Qaida's deputy leader, Atiyah Abd al-Rahman, was killed in a U.S. drone strike in the same region on August 22. Pakistan's tribal area is a known refuge for Taliban and al-Qaida-linked militants.

Rahman had risen to the number-two spot in al-Qaida, after U.S. special forces killed the terror network's leader, Osama bin Laden, during a covert raid in the Pakistani city of Abbottabad on May 2.

And earlier this month, Pakistan's military said security forces had arrested senior al-Qaida leader, Younis al-Mauritani, and two other al-Qaida operatives during an operation in the southern city of Karachi.

Bin Laden reportedly tasked Mauritani with targeting economic interests in the United States, Europe and Australia.

The White House praised the arrest of Mauritani as an example of the longstanding partnership between the U.S. and Pakistan in fighting terrorism.