Three more Al-Qaeda suspects, including an alleged senior militant, were killed Monday in a drone strike in southern Yemen, a local official said.

The attack was the latest in an intensified air campaign that has killed more than 40 suspected Al-Qaeda militants, including 30 on Sunday alone, days after the jihadist network\'s Yemen affiliate vowed to fight against Western "crusaders."

The United States is the only country operating drones over Yemen, but US officials rarely acknowledge the covert drone programme.

The Yemeni official, requesting anonymity, said that shortly after midnight (2100 GMT Sunday) a drone fired a missile at an off-road vehicle carrying three men in the southern Shabwa province, seen a stronghold for Al-Qaeda in the Arabian Peninsula (AQAP).

Witnesses confirmed that the vehicle had been completely destroyed and said they saw the charred remains of three individuals.

They said an unmarked commando helicopter arrived shortly thereafter to retrieve the bodies.

"The operation seems to indicate that one of the dead could be an important leader of Al-Qaeda," one witness told AFP.

Yemen\'s interior ministry meanwhile said that 10 people suspected of wanting to join Al-Qaeda had been arrested at a security roadblock in Shabwa.

On Sunday US drones fired "several missiles" into an AQAP training camp in the rugged Wadi Ghadina region in the southern province of Abyan, killing more than 30 militants, a tribal chief said.

A defence ministry statement confirmed that "several" militants were killed in an attack on "training camps."

On Saturday a drone strike in the central province of Baida killed 10 Al-Qaeda suspects and three civilians, according to the official Saba news agency. It did not say who carried out the attack.

The weekend attacks came less than a week after AQAP chief Nasser al-Wuhayshi pledged in a rare video appearance to fight Western "crusaders" everywhere.

"We will continue to raise the banner of Islam in the Arabian Peninsula and our war against the crusaders will continue everywhere in the world," he said in the video posted online.

AQAP is seen as one of the most sophisticated affiliates of the global terror network, and has been linked to several failed attacks on the US homeland.

Yemen\'s President Abdrabuh Mansur Hadi has defended the use of drones, despite criticism from rights groups concerned about civilian casualties.