SANAA, Yemen -- Hundreds of Yemeni troops loyal to the internationally recognized president have launched an operation to drive al Qaeda and ISIS fighters out of southern coastal areas the extremists have seized amid the country's complex civil war, security officials said Sunday.
They said the forces loyal to President Abed Rabbo Mansour Hadi are receiving air support from the Saudi-led and U.S.-backed coalition, which until now has mainly targeted Shiite Houthi rebels. The aircraft struck targets in Mukalla, an al Qaeda stronghold and the capital of Hadramawt province, they said.
Residents in Mukalla told the Reuters news agency that Yemeni and allied Emirati troops had entered the city for the first time in a year.
"Coalition armored vehicles and the army entered Mukalla and al Qaeda fighters are departing," one unnamed witness told Retuers.
The deployment, which began a day earlier, is the latest operation against al Qaeda in Yemen's south. Troops loyal to Hadi also advanced Saturday in the town of Koud in the southern Abyan province, the province's governor said, killing 25 militants from the group in heavy clashes. The coalition has also carried out airstrikes against al Qaeda positions in the area.
The troops had been preparing for the offensive for months with the coalition's support, the officials said, adding that heavy fighting continued with al Qaeda gunmen in Abyan, near the cities of Zinjibar and Jaar. Residents say al Qaeda fighters are holing up in buildings and digging trenches to defend their positions from the advancing troops, and the security officials say the extremists have also laid mines.
There were no official casualty figures from the weekend's fighting, but medical officials and witnesses said ambulances were transporting wounded and killed al Qaeda fighters in the area. Hadramawt residents said Apache helicopters and F-16 warplanes were sighted over coastal areas including Mukalla, and had struck several targets, including port facilities.
All residents spoke on condition of anonymity for fear of reprisals. The officials spoke on condition of anonymity because they were not authorized to brief reporters.
Al Qaeda's affiliate in Yemen, AQAP, viewed by Washington as the group's most dangerous offshoot, has exploited the conflict between the rebels and government forces to expand its footprint.
Yemen's conflict pits the government, backed by the Saudi-led coalition, against the Houthis, allied with a former president. The Houthis took over the capital, Sanaa, in September 2014, and the U.S.-backed coalition began airstrikes against them in March 2015.
The United Nations says peace talks held last week in Kuwait between the warring parties will continue.
The war has devastated Yemen, the Arab world's poorest country, with many unable to access hospitals, schools or electricity. More than 14 million Yemenis lack access to sufficient food, and some 2.4 million people have been displaced.
In over a year since the Saudi intervention, the war has killed nearly 9,000 people - a third of them civilians, according to the U.N.