Heavy gunfire and running street battles between Malian troops and suspected Islamist insurgents erupted in the town of Gao only hours after a foiled suicide bomb attack.
It was reported French soldiers may have also taken part in the clashes.
Much of the fighting has centred on a police station where al Qaeda linked rebels were said to be holed up.
Malian Defence Minister Yamoussa Camara said three of the Islamist raiders who has sneaked back into the town were killed and 11 taken prisoner, while some Malian soldiers were wounded in the street fighting.
A doctor in Gao’s hospital, Noulaye Djiteyi, said three civilians were killed and 11 injured by gunshot wounds. The
casualties were hit by stray bullets in the gunbattle.
Gao was retaken by French and Malian troops just over two weeks ago. It was thought all of the Islamists had been driven out.
The rapid speed of the French intervention to oust insurgents from Mali’s north appears to have left the rear of their forward lines vulnerable, with Mali’s weak army unable to make safe the recaptured zones.
The surprise raid by insurgents comes after Saturday’s suicide bomber attempt near a checkpoint at a northern entrance to the town.