The Malian government has accused Al-Qaeda of backing Tuareg rebels who fought troops over a town in the northeast Thursday in the latest push in their insurgency.

The rebels, many of whom recently returned from fighting in Libya, last week announced a fresh offensive in their quest for greater autonomy for their nomadic desert tribe, and on Tuesday attacked the town of Aguelhoc.

In a statement Thursday, the defence ministry said the Aguelhoc assault was carried out by "AQIM jihadis, MNLA forces and others".

It was referring to Al-Qaeda in the Islamic Maghreb (AQIM) and the Azawad National Liberation Movement (MNLA), a rebel group.

This was the first time an official connection has been made between AQIM, Al-Qaeda's north African arm, and the Tuareg rebels.

A resident at the local teacher's training college, Alhousseini Toure, added that Islamists had been among the attackers, who shouted: "God is Greatest."

Heavy fighting was reported Thursday in Anderamboukane, also in the northeast, in the rebels' first major offensive in the region in three years.

Both sides claimed to be in control by the end of the day.

"Fighting is over in Anderamboukane, the MNLA is in control of the town," said the movement's spokesman Moussa Ag Assarid.

Another spokesman, Moussa Salem, said rebels held the town's military camp and had "seized four armoured vehicles and other military equipment. We also have eight military prisoners. The Malian army could not resist the force of our attack."

But a military official speaking on condition of anonymity from the regional headquarters in Gao denied this.

"The Malian army had no armoured vehicles in town and we are in control of the situation in Anderamboukane. The attackers are in disarray. Helicopters intervened causing panic among the attackers. The fighting is over," he said.

"It is not the time for negotiations, we are defending our country and from now on we will attack them," he added.

The town of 3,000 people on the border of Niger is some 100 kilometres (60 miles) from Menaka, one of three towns attacked last week by Tuareg rebels.

Mali's defence ministry said 45 rebels and two soldiers were killed in two days of fighting last week. The Tuareg claim the military took heavier losses.

Anderamboukane is known for hosting a popular Tuareg festival in January of every odd year.

Also Thursday, Tuareg rebels took control of a deserted military camel cavalry camp in central Mali, several hundred miles to the west of Anderamboukane.

A government official and a police source told AFP that Tuareg rebels appeared in about a dozen vehicles and planted a flag in the camp in Lere.

The MNLA, formed in late 2011, has taken up the decades-old demand for independence by the tribe, which has fought rebellions in Mali and Niger in the 1960s, 1990s and early 2000, with a resurgence between 2006 and 2009.

"This new organisation aims to free the people of Azawad from the illegal occupation of its territory by Mali," the organisation said in its first press statement in October 2011.

"Our aim is to flush out the Malian army in several northern towns," rebel spokesman Salam told AFP last week.

Foreign Minister Soumeylou Boubeye Maiga said this week the army was in control of the three towns, and that the government was ready to listen to Tuareg concerns but would not accept violence.

"We have no problem with the Tuareg. They are Malian citizens like any other who can have expectations, aspirations and impatience," Maiga said on the sidelines of a security meeting in Nouakchott.

"Some groups have demands which they try to make known through violence and with weapons ... all these demands can be expressed without turning to violence.

"The Malian state is ready to listen but it will not accept actions which threaten the country's security and stability. Mali's unity and indivisibility is guaranteed."