(Reuters) - Tribal fighters entered the Yemeni coastal town of Mukalla on Saturday, seeking to drive out suspected al Qaeda fighters who took control 48 hours earlier, residents said.

An alliance of tribal gunmen, who drove into the coastal town in pickup trucks, has pledged to restore security after the Islamist militants drove the army out and ransacked buildings, broke into banks and freed prisoners from Mukalla's main jail.

(Reporting by Mohammed Ghobari; Writing by Dominic Evans; Editing by Robin Pomeroy)