A security official in Yemen says heavily armed al-Qaida militants laid a siege to a coast guard camp in a southern town, shelling its barrack and killing four coast guard members.

The official says al-Qaida militants used anti-aircraft guns mounted on pickup trucks Sunday in the coastal town of al-Shahr in the province of Hadramawt overlooking the Gulf of Aden.

The official says the military deployed troops and tanks and fought with the al-Qaida militants. He spoke on condition of anonymity because he was not authorized to brief reporters.

Witness Ahmed Ben Hamel said he saw tanks shelling nearby buildings suspected to have been taken over by al-Qaida militants.

Yemen's local branch of al-Qaida is considered the world's most dangerous by the U.S. and has claimed a number of attacks.