Yemeni troops killed 13 militants in a raid outside the southern city of Mukalla on Sunday in which two soldiers also died, the army said, extending a struggle to restore security in an area ruled until last month by al-Qaida.
"Special forces and the army gained complete control over the site backed up by helicopters from the Arab coalition, which dealt with groups of terrorists spread around the area who were fleeing," an army statement said.
"A search confirmed that these fighters were about to carry out a surprise terrorist attack on some military command centers at dawn this morning."
A security official said the fighters were from al-Qaida.
Hours later three more militants were killed as a car bomb they were preparing detonated in the courtyard of a house in the Rawkab area where the raid had taken place, residents and a security official said. They said that security forces were combing the area for more gunmen and explosives.
Before being forced out, al-Qaida militants took advantage of more than a year of war between Iran-allied Houthi forces and supporters of Saudi-backed President Abd-Rabbu Mansour Hadi to carve out a mini-state stretching across much of the Arabian Peninsula country's southern coast, including Mukalla.
The United Arab Emirates trained and funded Yemeni forces for months and backed up their re-conquest of Mukalla on April 25 with air strikes.
Militants in Yemen's branch of Islamic State have carried out a series of suicide attacks on all parties to Yemen's tangled conflict, killing 25 police recruits in a bombing outside Mukalla last week.