(CNN) -- Two top al Qaeda terrorists have been killed in a U.S. missile strike on a building in northern Pakistan on New Year's Day, according to two senior U.S. officials.
A U.S. official says Fahid Mohammed Ally Msalam was al Qaeda's operations director for Pakistan.
The two men, both Kenyans, were on the FBI's Most Wanted Terrorist list, one of the officials said, adding that they were believed to have been responsible for the September suicide bombing at the Marriott hotel in Islamabad, Pakistan.
The pair was also under indictment for the 1998 bombings of U.S. embassies in Kenya and Tanzania, which killed more than 220 people and injured scores of others, according to the officials.
The officials identified the men as Usama al-Kini, who was also known as Fahid Mohammed Ally Msalam, and Sheikh Ahmed Salim Swedan, described as a top lieutenant to al-Kini.
The officials could not confirm the particulars of the attack that killed them. But The Washington Post reported the men were slain in a missile strike by a CIA pilotless drone aircraft.
The men were believed to have been behind numerous suicide attacks in Pakistan, including ones targeting police facilities and a Pakistani air force bus.
The sources refused to speak on the record because they are not authorized to speak officially about this incident.
One of the senior U.S. officials said the men were "involved in working with explosives" when the strike occurred.
The CIA and FBI would not comment.
CNN previously reported two missiles were fired near the Pakistan-Afghanistan border on New Year's Day.
One of the officials said al-Kini was al Qaeda's operations director for Pakistan and believed to be behind the September 20 Marriott car bombing that killed 53 people. The official also said al-Kini also was behind a failed attempt to kill Benazir Bhutto shortly after she returned to Pakistan from exile in October 2007.
CNN Senior Producer Kevin Bohn contributed to this story.