Anwar al-Awlaki, a US-born cleric linked to al Qaeda's Yemen-based wing, was killed in an air strike on Friday, Yemeni and US officials said, removing a 'global terrorist' high on a US wanted list.

Awlaki's killing, if confirmed, deprives al Qaeda in the Arabian Peninsula (AQAP) of an eloquent preacher seen as its most talented English-language propagandist who has advocated - and been implicated in - attacks on the United States.

Some of the hijackers in the September 11, 2001 attacks attended mosques where Awlaki preached in the United States.

His death could be a boon for Yemen's embattled President Ali Abdullah Saleh, clinging to power despite months of popular protests, factional violence and international pressure.

It was not immediately clear if Yemen had carried out the raid or if Awlaki had been killed by a US drone strike. A US drone aircraft targeted but missed Awlaki in May.

'The terrorist Anwar al-Awlaki has been killed along with some of his companions,' the Yemeni Defence Ministry said in a statement texted to journalists, but gave no details.

A senior US official confirmed Awlaki's death, but gave no details. 'I can confirm he's dead,' the official said.

A Yemeni security official said Awlaki, 40, who is of Yemeni descent, was hit in a morning air raid in the northern al-Jawf province that borders oil giant Saudi Arabia. He said four suspected al Qaeda members were killed with him.

The Yemen embassy in Washington said Awlaki had been killed 8 km from the town of Khashef in Jawf province, about 140 km east of Sanaa, at about 9:55am. (0655 GMT).

Yemeni authorities previously and erroneously reported that Awlaki had been killed in 2009.

The US has stepped up drone strikes in Yemen to try and keep al Qaeda off balance and prevent it from capitalising on the strife and chaos gripping the nation.

AQAP usually confirms the deaths of its members or affiliates on Internet posts a few days after the attack.

'If he is dead, Awlaki will be difficult to replace,' said Jeremy Binnie, a terrorism and insurgency analyst at IHS Jane's in London. 'It's a blow for AQAP's international operations. Awlaki has helped the group build its international profile.'

US officials say Awlaki was linked to a botched AQAP attempt to bomb a Detroit-bound transatlantic airliner on December 25, 2009 and had contacts with a US Army psychiatrist who killed 13 people at a US military base a month earlier.

US authorities have branded him a 'global terrorist' and last year authorised his capture or killing, but Sanaa had previously appeared reluctant to act against him.

Awlaki was not a senior Islamic cleric, nor a commander of AQAP, which is led by a Yemeni named Nasser al-Wuhayshi, but he played a key role in the group's global outreach.

'Awlaki's death won't hurt al Qaeda's operations because he didn't have a leadership role. But the organisation has lost an important figure for recruiting people from afar,' said Said Obeid, a Yemeni analyst on al Qaeda.

Henry Wilkinson, head analyst at risk consultancy Janusian in London, said Awlaki's demise would have little impact on AQAP's local operations, but added: 'He was a rare talent who could reach out and recruit and mobilise. If the US have killed Awlaki, then they have achieved a major target.'

Yemen has been mired in turmoil after eight months of mass protests demanding that Saleh step down, something he has now reiterated he will do only if his main rivals do not take over.

'Because if we transfer power and they are there, this will mean that we have given into a coup,' Saleh told The Washington Post and Time magazine in an interview published on Friday, a week after he made a surprise return from Saudi Arabia.

He had been recuperating in Riyadh from a June bomb attack on his Sanaa compound that badly burned and wounded him.-Reuters