France now has 1,400 troops on the ground in Mali, more than half the total of 2,500 it plans to deploy in its former colony, Defence Minister Jean-Yves Le Drian said on Thursday.

The troops have been sent to the West African state as part of an operation designed to help the Malian army regain control of the north of the country from Islamist groups.

Troop numbers have risen quickly since the first French forces were deployed on January 11 in response to an offensive by Islamist fighters who seized the central town of Konna.

The Malian army, backed by French troops, was still fighting to retake Konna on Thursday.

The French are also involved in a battle for the town of Diabaly, which is within government-controlled territory and was seized by the Islamists on Monday in a counter offensive launched after the first French airtrikes around Konna.