A drone strike in the eastern Yemeni province of Shabwa last month killed the top religious cleric for Al-Qaeda in the Arabian Peninsula, a source close to AQAP said on Tuesday. "A drone strike had targetted Sheikh Adel al-Abab's vehicle but he escaped and fled to a mountainous region where a raid by another drone killed him immediately," the source told AFP on condition of anonymity. Abab had graduated from an Islamic studies centre, the Dawa Centre, in Sanaa and had served as AQAP's top religious cleric. US drone strikes against Al-Qaeda militants are frequent in Yemen, home to the franchise seen by the United States as the jihadist network's deadliest and most active. AQAP is led by Nasser al-Wuhayshi, who in July 2011 reaffirmed the group's allegiance to Ayman al-Zawahiri, head of the worldwide Al-Qaeda network since the killing in May of its founder, Osama bin Laden. US drones strikes in Yemen nearly tripled in 2012 compared with 2011, from 18 to 53, according to the New America Foundation, a Washington-based think-tank. In October 2000, Al-Qaeda militants attacked US Navy destroyer the USS Cole in Yemen's port of Aden, killing 17 sailors and wounding 40 more.