Yemeni security officials and witnesses say an ambush in the port city of Mocha killed 44 anti-rebel fighters.

The officials said Tuesday that the ambush by Shiite rebels, known as Houthis, took place the day before.

In a separate development, security officials say more than 20 Houthi fighters were killed Monday and Tuesday in clashes in the central Marib province.

The officials, who are neutral in a conflict that has split the armed forces, spoke on condition of anonymity because they weren't authorized to brief reporters. Witnesses declined to give their names for fear of reprisals.

Yemen's fighting pits the Houthis and allied army units against forces loyal to the internationally recognized government, as well as southern separatists and militants.