Yemeni security officials say a local al-Qaida affiliate has stormed a government-controlled town in the southern Abyan province.

The pro-government officials say al-Qaida attacked Jaar on Wednesday, exploiting the security vacuum that followed the recent defeat of Shiite Houthi rebels there. They say 20 fighters have been killed on both sides.

The extremists have also recently captured most of Abyan's capital, Zinjibar. Earlier this year, al-Qaida took advantage of the chaos of the civil war to seize parts of the sprawling Hadramawt province, including its capital.

Yemen's fighting pits the internationally recognized government against the Houthis and army units loyal to a former president. The U.N. says the conflict has killed at least 5,700 people since March.

The officials spoke anonymously because they are not authorized to talk to reporters.