Yemeni authorities have released 25 activists hours after they were arrested in the south following deadly clashes between police and separatists, activists said on Sunday.

The capital of the formerly independent South Yemen, Aden, was cautiously calm on Sunday, a day after a gathering by separatists commemorating the north’s seizure of the south in 1994 turned into a gunbattle.

Two protesters were killed and one man was left “clinically dead” in the clashes which took place in Aden’s Mansura district, a medical official from Al Naqib hospital said.

Further east, in the town of Seyun in Hadramawt province, one protester was killed and four others were wounded on Saturday when police opened fire on another group of demonstrators, activists said.

Meanwhile, 25 activists, including Yahia Saleh Said, deputy head of the Southern Movement’s superior council who were arrested were released a few hours later on Saturday.