U.S. fighter jets pounded al-Qaida targets in Yemen for a second straight day on Friday, killing eight militants, security and tribal sources said, as Washington steps up its air war against the militants.

Successive U.S. administrations have kept up a drone war against al-Qaida in Yemen since soon after the Sept. 11, 2001 attacks.

Washington regards the Yemen branch as al-Qaida' most dangerous and holds it responsible for several plots to carry out attacks in the West.