More than 200 suspected al-Qaeda gunmen have taken control of the south Yemen city of Zinjibar after two days of heavy fighting with security forces that left 16 dead.

The Yemeni opposition accused embattled President Ali Abdullah Saleh of having allowed Zinjibar, capital of Abyan province, to fall to the gunmen to raise fears concerning al-Qaeda and boost his flagging international support.

The suspected al-Qaeda fighters “were able to gain control of the city of Zinjibar…and took over all government facilities,” except for the headquarters of the 25th mechanised brigade, which is besieged by militants, the security official said.

Residents reported that there had been heavy fighting in the city on Friday and Saturday, and that gunmen had freed dozens of prisoners from the main prison in Zinjibar.

One witness said on condition of anonymity that the gunmen executed soldiers who surrendered, and that residents were not able to bury them.

Dozens of families fled towards Aden, the main city in the south, among them Nazir Ahmed Said, who told the news agency he left because “the city is under the control of gunmen who say they are from al-Qaeda.”

“Saturday morning, the gunmen called on residents by loudspeaker to go out and reopen their shops, but few answered the call because they are afraid,” he added.

The security official estimated that more than 200 militants had attacked the city.

“The lack of concern from the authorities is unfortunate,” he said, adding that “the leadership in Abyan province left the area before it exploded.”