SANAA, Yemen (AP) — In a significant new blow to al-Qaida, U.S. airstrikes in Yemen  on Friday killed Anwar al-Awlaki, an American militant cleric who  became a prominent figure in the terror network's most dangerous branch,  using his fluent English and Internet savvy to draw recruits for  attacks in the United States.
The  strike was the biggest U.S. success in hitting al-Qaida's leadership  since the May killing of Osama bin Laden in Pakistan. But it raises  questions that other strikes did not: Al-Awlaki was an American citizen  who has not been charged with any crime. Civil liberties groups have  questioned the government's authority to kill an American without trial.
The  40-year-old al-Awlaki was for years an influential mouthpiece for  al-Qaida's ideology of holy war, and his English-language sermons urging  attacks on the United States were widely circulated among militants in  the West.
But U.S. officials say  he moved into a direct operational role in organizing such attacks as  he hid alongside al-Qaida militants in the rugged mountains of Yemen.  Most notably, they believe he was involved in recruiting and preparing a  young Nigerian who on Christmas Day 2009 tried to blow up a U.S.  airliner heading to Detroit, failing only because he botched the  detonation of explosives sewn into his underpants.
Yemen's Defense  Ministry said another American militant was killed in the same strike  alongside al-Awlaki — Samir Khan, a U.S. citizen of Pakistani heritage  who produced "Inspire," an English-language al-Qaida Web magazine that  spread the word on ways to carry out attacks inside the United States.  U.S. officials said they believed Khan was in the convoy carrying  al-Awlaki that was struck but that they were still trying to confirm his  death. U.S. and Yemeni officials said two other militants were also  killed in the strike but did not immediately identify them.
Washington  has called al-Qaida in the Arabian Peninsula, as the branch in Yemen is  called, the most direct threat to the United States after it plotted  that attack and a foiled attempt to mail explosives to synagogues in  Chicago.
In July, U.S. Defense  Secretary Leon Panetta said al-Awlaki was a priority target alongside  Ayman al-Zawahri, bin Laden's successor as the terror network's leader.
The  Yemeni-American had been in the U.S. crosshairs since his killing was  approved by President Barack Obama in April 2010 — making him the first  American placed on the CIA "kill or capture" list. At least twice,  airstrikes were called in on locations in Yemen where al-Awlaki was  suspected of being, but he wasn't harmed.
Friday's  success was the result of counterterrorism cooperation between Yemen  and the U.S. that has dramatically increased in recent weeks —  ironically, even as Yemen has plunged deeper into turmoil as protesters  try to oust President Ali Abdullah Saleh, U.S. officials said.
Apparently  trying to cling to power by holding his American allies closer, Saleh  has opened the taps in cooperation against al-Qaida. U.S. officials said  the Yemenis have also allowed the U.S. to gather more intelligence on  al-Awlaki's movements and to fly more armed drone and aircraft missions  over its territory than ever before.
The operation that killed  al-Awlaki was run by the U.S. military's elite counterterrorism unit,  the Joint Special Operations Command — the same unit that got bin Laden.
A  U.S. counterterrorism official said American forces targeted a convoy  in which al-Awlaki was traveling with a drone and jet attack and believe  he's been killed. The official was not authorized to speak publicly and  spoke on condition of anonymity.
The  Yemeni government announced that al-Awlaki was "targeted and killed"  around 9:55 a.m outside the town of Khashef in mountainous Jawf  province, 87 miles (140 kilometers) east of the capital Sanaa. It gave  no further details.