A US drone attacked a Saudi Al-Qaeda leader in southern Yemen on Thursday, but missed and killed two local Al-Qaeda members, a security source and witnesses told AFP.
The drone had targeted the Saudi as he drove to the home of local Al-Qaeda men, the security source said, asking not to be identified.
When the two local Qaeda men rushed out in their own car, they were hit and killed by the drone.
The security source did not specify that the unmanned aircraft was American and there was no official word from the Yemeni authorities on who carried out the strike.
But the witnesses insisted it was a US drone that fired the missile.
The defence ministry confirmed the killing of two brothers, but did not elaborate on the circumstances of their deaths. Security sources identified the two brothers as Abdullah and Mubarak al-Harad.
Witnesses said they saw a missile fired by an aircraft hit the two brothers in the province of Shabwa, where Al-Qaeda is well entrenched. The men died instantly.
A third person was wounded in the attack in the town of Nissab, the witnesses added.
The Washington Post reported in November that President Barack Obama's administration had deployed unmanned Predator drones in Yemen to hunt for Al-Qaeda operatives.
Yemen has come under intense pressure to crack down on jihadists' local franchise, Al-Qaeda in the Arabian Peninsula, since a December 2009 attempt to blow up a US airliner that was claimed by AQAP.
Washington has expressed fears that Al-Qaeda could take advantage of a prolonged political crisis in Yemen, where President Ali Abdullah Saleh has faced mass protests since late January calling for him to step down.
Saleh, who is clinging to power, has been a close US ally in Washington's fight against Al-Qaeda. Political violence has claimed the lives of 150 people since the start of this year.
In Abyan -- another restive southern province where Al-Qaeda is active -- nine people, including four policemen and a soldier, were killed in clashes between security forces and Al-Qaeda gunmen on Wednesday, a security official and medics said.
The authorities blame Al-Qaeda for the violence.
Clashes erupted when armed men fired three mortar rounds at two police vehicles leaving the riot-police headquarters in the provincial capital Zinjibar.
Four policemen and a soldier who were passing by were killed, the security official said, adding that seven policemen were wounded in the attack and subsequent clashes in the town centre.
A medical official said four of 16 civilians who were admitted to the hospital "succumbed to their wounds".
On Sunday, three policemen were killed in a similar attack in the country's southeastern province of Hadramaut.
An AQAP leader on Wednesday vowed revenge for the killing of Al-Qaeda leader Osama bin Laden in a US special forces raid in Pakistan announced by the White House late on Sunday.
"We will take revenge for the death of our Sheikh Osama bin Laden and we will prove this to the enemies of God," he told AFP, contacted by telephone from Abyan.
"They will see what they haven't expected... We are preparing a plan to continue jihad in the coming period."