Radical U.S.-born cleric Anwar al-Awlaki has been killed in an airstrike in Yemen that news reports say was orchestrated by the U.S. Central Intelligence Agency.

Missiles fired from a drone aircraft killed Awlaki early Friday as he rode in a convoy in eastern Yemen.

President Barack Obama called Awlaki's death a "major blow" to one of al-Qaida's most active affiliates.

Speaking to a military audience outside Washington, Mr. Obama said the operation that killed Awlaki is proof that the terrorist group and its affiliates cannot find a safe haven anywhere in the world.

Quick Facts: Anwar al-Awlaki

Anwar al-Awlaki was a notorious and outspoken figure within al-Qaida, and a leader of the terrorist network's wing in Yemen.

Awlaki, whose group in Yemen is known as al-Qaida in the Arabian Peninsula, was believed to have been the target of a U.S. drone attack in May. He also escaped an air attack that killed 30 people last year. He was born in New Mexico, USA in 1971 (Yemeni parents, fluent in Arabic and English). He served as an imam at several U.S. mosques, including one in the western city of San Diego that was frequented by two men who were involved in the September 11, 2001 attacks against the United States. After Awlaki traveled to Yemen, he became an Internet sensation with a loyal following, including many radicals around the world who listened to recordings of his preachings. He was a vocal critic of America and was suspected of motivating others to commit violence against U.S. interests. Was wanted by authorities in US and Yemen. Yemeni authorities charged Awlaki with "inciting violence against foreigners" for the 2010 killing of a French oil industry worker in Yemen. Believed to have helped Nigerian suspect arrested for attempted 2009 Christmas Day bombing of US airliner. Acted as advisor to U.S. Army psychiatrist accused of carrying out mass shooting at military base that left 13 dead in 2009.

Western news organizations quote U.S. officials as saying the raid was coordinated by the CIA and led by U.S. Joint Special Operations Command, the counterterrorism unit that led the May operation killing Osama bin Laden.

Several other suspected militants were killed in the operation, including Samir Khan, an American of Pakistani origin who produced an English-language magazine for al-Qaida on the Internet.

Awlaki was linked to the group al-Qaida in the Arabian Peninsula, based in Yemen. He was wanted by both the U.S. and Yemen for his suspected role in terrorist attacks.

Those attacks included the December 2009 attempted bombing of a U.S. airliner that was approaching the U.S. city of Detroit.

Authorities believe Awlaki advised the suspected bomber, Nigerian Umar Farouk Abdulmutallab. Investigators believe Awlaki also played a role in a deadly attack, a month earier, at a U.S. military base.

They say Awlaki may have advised U.S. Major Nidal Malik Hasan, who is accused of killing 13 people in the attack.

Awlaki's death comes with Yemen in a political crisis, marked by heightened calls for President Abdullah Saleh's resignation.

Activists say thousands of anti-government protesters rallied in the capital, Sana'a on Friday and in the southern city of Taiz.

In an interview with The Washington Post and Time magazine this week, Mr. Saleh said a political transition plan crafted by Yemen's Gulf neighbors made it clear that "all elements" contributing to the country's civil unrest should be removed.

The president warned it would be "very dangerous" if his rivals, General Ali Mohsen al-Ahmar, who defected to the opposition, and Hamid al-Ahmar, a telecom tycoon and politician whose brother heads Yemen's most powerful tribal confederation, were to retain their positions after he resigns.

He said that outcome could "lead to civil war." Mr. Saleh has agreed to the plan crafted by the Gulf Cooperation Council three times since April.

However, each time he has backed out before the deal could be signed.

Some information for this report was provided by AP, AFP and Reuters.