Yemeni security and military officials say scores of al-Qaida militants have been killed in heavy clashes with the army, following an airstrike campaign this month by a Saudi-led coalition against al-Qaida positions in the area.

The officials say ground troops loyal to the internationally recognized government are advancing in Saturday's clashes in the town of Koud in the southern province of Abyan.

Al-Qaida's affiliate in Yemen, viewed by Washington as the group's most dangerous offshoot, has exploited the conflict between Shiite rebels and government forces to expand.

A Saudi-led coalition is battling the Shiite rebels, known as Houthis, and their allies.

The Houthis have held Yemen's capital, Sanaa, since September 2014, and their advance across the Arab world's poorest country brought the Saudi-led coalition into the war in March 2015.