SANAA, Yemen (AP) — Yemeni tribal leaders say a suspected U.S. drone strike has killed four alleged al-Qaida militants including a field leader in the country's south.

The tribal leaders said on Sunday that the operatives were killed when an unmanned aircraft targeted a group of al-Qaida militants in the district of Ahwar, one of al-Qaida's strongholds in the southern Abyan province.

They spoke on condition of anonymity for fear of reprisals.

Al-Qaida in the Arabian Peninsula, as the Yemeni affiliate is known, has long been considered the global network's most dangerous branch and has attempted to carry out attacks inside the U.S.

Yemen was plunged into civil war more than three years ago. Al-Qaida and the Islamic State affiliate have exploited the chaos to expand their presence in the country.