Fighting erupted Tuesday in northern Mali between government troops and a group of Tuareg rebels vying for control of the town of Menaka, witnesses said.

"The rebels haven't entered the town yet. They are firing from afar and the Malian army is shooting back," a resident told AFP by phone.

An independent source confirmed the battle was underway: "The two camps are fighting for control of the town" of Menaka which is in north-eastern Mali close to the Niger border.

"Some are saying the rebels have entered the town and others say not. The situation is somewhat unclear," an NGO official from the region told AFP, on condition of anonymity.

The Malian army last week boosted its presence in northern Mali, placing hundreds of men in Tinzawaten, a town near the Algerian border.

In order to reach this town the army passed through the mountainous Zackac region where rebel Tuareg forces were living. The Tuareg abandoned their positions and split up into three groups.

"It is one of these groups which attacked Menaka. It is not excluded that other groups will attack other towns," added the independent source.