Yemen's US-backed campaign against Al-Qaeda in the Arabian Pensinsula (AQAP) was expected to be high on the agenda of Abdrabuh Mansur Hadi's meeting with President Barack Obama later on Thursday.

Washington regards AQAP, a merger of militants in Yemen and neighboring Saudi Arabia, as the worldwide anti-US network's most active and dangerous branch.

The unmanned aircraft "raided an Al-Qaeda vehicle in the Wadi Ser area destroying it and killing four militants," the Yemeni security official told AFP, speaking on condition of anonymity.

It was the third deadly drone strike in five days to hit Al-Qaeda in Yemen.

On Tuesday, a US drone killed three people in the southern province of Shabwa.

On Saturday, a drone killed six people in the Mahfad mountains of neighboring Abyan province.

The United States, the only country to operate drones in the region, has sharply increased its use of them in the countries such as Yemen, Pakistan and Afghanistan over the past two years.

US drones strikes in Yemen nearly tripled in 2012 compared to 2011, from 18 to 53, according to the New America Foundation, a Washington-based think-tank.

Washington claims the airstrikes target militants, but reports on the ground show that civilians have been the main victims of the attacks.

BA/BA