SANAA

 At least 20 Houthi militants were killed Friday in an ambush by unidentified militants in Yemen's southern Lahij province, security sources have said.

According to the sources, gunmen set an ambush in the Wahat region between the Aden and Lahij provinces, attacking a group of Houthis with light and medium weapons, killing 20 of them.

The sources gave no further details about the attack or whether there had been any casualties among the attackers.

Politically fractious Yemen has been rocked by turmoil since last September, when pro-Houthi forces overran capital Sanaa, from which they have since sought to extend their influence to other parts of the country as well.

Several Arab states, all of them allies of Washington, have joined a Saudi-led military offensive that kicked off Wednesday with a string of airstrikes against Houthi positions and assets in Yemen, including some in capital Sanaa.

Some Gulf countries say Yemen's Houthi insurgency enjoys the backing of Shiite Iran.