ADEN (Reuters) - At least four suspected al Qaeda members were killed in an apparent U.S. drone strike on a vehicle in central Yemen, residents said on Wednesday, part of an escalating campaign against the Islamist militant group.

They said the attack in Amqoz in the Moudiya district of Abyan province took place around midnight on Tuesday. Their vehicle was completely burned and the four bodies inside badly charred, they added.

Residents also reported hearing missile strikes on a suspected al Qaeda outpost in Wadi al-Naseel area, also in Abyan province, but said the number of casualties was unknown.

Abyan is one of several provinces in central and southern Yemen where Al Qaeda in the Arabian Peninsula (AQAP) and its local affiliate Ansar al-Sahria operate.

The United States has repeatedly attacked AQAP, the Yemeni arm of the militant group, in strikes this month from aircraft and unmanned drones in what U.S officials says is a campaign to degrade the group’s ability to coordinate militant attacks abroad.

AQAP has exploited nearly two years of civil war in Yemen to recruit followers and cement its dominance in central and southern parts of the Arab country.

The Pentagon said this month that a March 2 strike against AQAP killed Yasir al Silmi, also know as Mohammed Tahar, a former detainee from the U.S. detention center at Guantanamo Bay, Cuba.