Yemeni security officials and witness say al-Qaida forces are withdrawing from two coastal cities east of the key port of Aden following tribal-led negotiations.

The withdrawal from the cities of Zinjibar and Jaar will take less than a week. The officials spoke on condition of anonymity because they weren't authorized to brief the press, while witnesses did so out of safety concerns.

Late last month, forces loyal to Yemen's internationally recognized government drove out al-Qaida militants from what had been their stronghold further down the coast, the city of Mukalla, a year after they captured it.

Extremists such as al-Qaida have gained ground amid the chaos that has reigned in Yemen since 2014. Shiite Houthi rebels are fighting the internationally-backed government, which is allied with a Saudi-led U.S.-backed coalition.