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

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 militant 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 program.
  
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).
  
A defense ministry statement confirmed that "several" militants were killed in an attack on "training camps."