Residents from central Yemen on Wednesday said at least four suspected al Qaeda members were killed in an apparent U.S drone strike on a vehicle in Abyan province as part of an escalating campaign against the militant group, Reuters reported.

They said the attack in Amqoz in the Moudiya district of Abyan province took place around midnight on Tuesday. 

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, reported Reuters.

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, reported Reuters.