A US drone strike has killed three suspected al-Qaeda members in Yemen in the second such attack in three days, a Yemeni military official and tribal sources said.

The official said the attack took place early on Tuesday in the town of Saeed in Shabwah province and targeted a car carrying the suspected fighters.

"The car in which the three were travelling - two Yemenis and a Saudi - was blown to pieces and all of them were killed outright," a tribal source told the AFP news agency, speaking on condition of anonymity.

One of the fighters was a known Saudi member of al-Qaeda's branch in Yemen, some other tribal sources told the Associated Press.

Another raid in the southern province on Saturday killed six suspected al-Qaeda members.

Raids intensified

The US, the only country to operate drones in the region, has increased its use of them against al-Qaeda targets in Yemen over the past two years.

Washington regards Al-Qaeda in the Arabian Peninsula (AQAP), a merger of fighters in Yemen and neighbouring Saudi Arabia, as the worldwide network's most active and dangerous branch.

Several AQAP leaders have been killed in US drone strikes, most recently the network's deputy leader Saeed al-Shehri whose death was confirmed by the fighters on July 17.

AQAP took advantage of the weakness of Yemen's central government during an uprising against now-ousted president Ali Abdullah Saleh in 2011 to seize large swathes of territory across the south and east.

Washington has given strong support to the efforts of Saleh's successor, President Abdrabuh Mansur Hadi, to reassert central government control.

President Barack Obama is to host Hadi for White House talks on Thursday.