Last Updated Jun 16, 2015 1:26 AM EDT
WASHINGTON -- Two notorious terrorist leaders were believed to have been killed in separate strikes made public Monday.
Nasir al-Wuhayshi, the head of al Qaeda in the Arabian Peninsula (AQAP), was targeted by a CIA drone strike in Yemen within the past several days. Although his death has not been confirmed by U.S. intelligence, one official told CBS News the indications are that he was killed.
UPDATE: AQAP released a statement early Tuesday morning via its online media portal saying al-Wuhayshi had been killed and naming his deputy, Qassim al-Rimi, as the group's new leader. U.S. officials have yet to confirm the death of al-Wuhayshi, however.
Wuhayshi was once the personal secretary to Osama bin Laden, before rising to lead AQAP -- the most dangerous branch of al Qaeda. He also served as deputy to al Qaeda leader Ayman al-Zawahiri, and had recently been given the title of manager of al Qaeda's global operations.
Among other attacks, AQAP was behind the attempt by the so-called underwear bomber to blow up a U.S. airliner over Detroit. It also claimed responsibility for the attacks carried out by two brothers in Paris earlier this year which left 11 dead.
CBS News senior security contributor and former CIA Deputy Director Mike Morell said that, if confirmed, the killing of al-Wuhayshi would represent "the most significant counterterrorism action by the United States since the killing of Osama bin Laden."
Mokhtar Belmokhtar was the target of a separate strike, this one by U.S. F-15 Eagles which bombed a building in Libya where he was believed to be meeting with members of al Qaeda's North African affiliate, al Qaeda in the Islamic Maghreb, which he led.
Belmokthar was behind an attack on a natural gas facility in Algeria in which 39 people, including three Americans, were killed.