Yemeni security officials say a suspected U.S. drone strike has killed four alleged al-Qaida fighters in the country's central Marib province.

The officials say the men were killed on Wednesday and have yet to be identified but the area is a known al-Qaida hotbed.

They say that a day earlier, five other suspected al-Qaida operatives were also killed in a similar drone attack in the neighboring Shabwa province.

Al-Qaida in the Arabian Peninsula is considered by Washington to be the group's most dangerous branch. It has expanded its territory in the chaos of Yemen's civil war.

The officials spoke on condition of anonymity because they are not authorized to release the information.