SANAA, Jan. 21 (Xinhua) -- An U.S. unmanned warplane struck a vehicle carrying al-Qaida suspects in northeast of Yemen's capital Sanaa on Monday, killing four operatives, the Yemeni Defense Ministry said.
"The airstrike hit the al-Qaida terrorists' car while they were driving in the Sanaa-Marib highway, killing all four operatives," the ministry said in a statement on its website.
It was the fourth such attacks by the U.S. drones in two days.
On Sunday, the government officials said eight al-Qaida operatives were killed in three successive drone raids overnight in the province of Marib, for which the Yemeni Interior Ministry on Monday said only two of the eight killed were al-Qaida members.
The continuing strikes have been igniting massive anger among conservative armed tribes against the central government and the United States.
The tribesmen usually cut roads linking major cities or cut oil supplies to protest against the drone strikes which they said had killed more civilians than terrorists.
The al-Qaida wing said that in the past few months the U.S. airstrikes pushed the tribesmen to join them (al-Qaida in the Arabian Peninsula) in carrying out more suicide bombings and assassinate senior Yemeni security officials inside Sanaa and the other cities.
Dozens of al-Qaida operatives have been killed in airstrikes since Yemeni President Abd-Rabbu Mansour Hadi was sworn in in February 2012, after a yearlong unrest weakened the control of the central government and allowed the militants to take over swaths of territory in the south.
The Yemeni government managed to recapture several of those southern cities in May last year.