GAO, Mali, Feb 21 (Reuters) - Malian troops opened fire on the mayor's office in the northern town of Gao with mounted machineguns on Thursday to try and dislodge suspected Islamist gunmen holed up inside, witnesses said.
Gunfire and explosions rang out in the early hours across the town, where French and Malian troops have been working to secure the area against bombings and guerrilla attacks by Islamist rebels, witnesses said.
French and Malian military spokesmen were not immediately available to comment on what led to the clash.
Gao is the biggest town in northern Mali, which was retaken from al Qaeda-linked Islamists last month in a lightning French offensive on behalf of the Malian government.
A Reuters journalist near the mayor's office said six Malian military pickups were deployed in the square nearby on Thursday and had opened fire with the heavy machineguns.
A Gao resident said he heard an explosion and then saw a Malian military vehicle on fire in a nearby street. The cause of the blast and fire was unclear.
Thursday's clashes came nearly two weeks after French and Malian forces fought hours of street battles with Islamists who had infiltrated the town. (Reporting by Emanuel Braun and Joe Penney; Additional reporting by David Lewis; Writing by David Lewis and Pascal Fletcher; Editing by Pravin Char)