The Yemeni government has released an official statement confirming that radical US-born cleric Anwar al-Awlaki has been killed along with several other suspected al-Qaeda operatives.
The government announced on Friday that Awlaki had been targeted and killed eight kilometres from the town of Khashef in the province of al-Jawf.
It said the operation was launched on Friday morning but gave no other details.
If the death is confirmed, Awlaki would be the most prominent al-Qaeda figure to be killed since Osama bin Laden's death in a US raid in Pakistan in May.
Tribal sources told Agence France-Presse that Awlaki, who was on a US wanted list, was killed in an air strike on two vehicles in Marib province, an al-Qaeda stronghold in eastern Yemen which borders al-Jawf.
One tribal source said the plane that carried out the strike was likely to be American, adding that US aircraft had been patrolling the skies over Marib for the past few days.
Friday's announcement was the second time the defence ministry has declared Awlaki dead.
In December last year, the Yemeni government announced he had been killed in an air strike, but it was later revealed that Awlaki was still alive.
In February, the US director of the National Counterterrorism Centre, Michael Leiter, told American congressmen that Awlaki probably posed "the most significant risk" to the US.
Awlaki, a US-Yemeni citizen who had eluded capture for years, was believed to be a key leader of al-Qaeda in the Arabian Peninsula (AQAP).
In April last year, a US official said President Barack Obama's administration had authorised the targeted killing of Awlaki, after American intelligence agencies concluded the cleric was directly involved in anti-American plots.
Awlaki was on a US kill-or-capture list and was accused by Washington of inspiring several attacks in the US.
The 40-year-old Awlaki is believed to have inspired and even plotted or helped coordinate some of the recent attacks on the US, including the failed Christmas Day 2009 bombing of an airliner heading for Detroit, Michigan, and the also unsuccessful plot to send mail bombs on planes from Yemen to the US in October.
American intelligence officials also believe Awlaki was linked to a US army major who allegedly shot dead 13 people in Fort Hood, Texas.
The American-born son of Yemeni parents rose to prominence as al-Qaeda's English-speaking voice and electronic messenger, spreading its terrorist credo via a blog, social media posts and email exchanges.
The Pakistani-American man who pleaded guilty to the May 2010 Times Square failed car bombing attempt told interrogators he was "inspired" by Awlaki after making contact over the internet.
