Armed men on Sunday took over two military camps in northern Mali, two elected officials told AFP, with a spokesman for an alliance of predominantly Tuareg armed groups claiming the attack.
The Malian military confirmed on social networks that the town of Lere, in the Timbuktu Region of northern Mali, had been attacked on Sunday.
A Malian military official told AFP it was "in the process of dealing with the situation."
"Armed men attacked the two (military) camps in the town of Lere on Sunday," an elected official from the town told AFP.
"After fighting, the armed men took the camps. We are waiting for reinforcement from the army, but for the moment it is the armed men who hold the camps," he added.
An official from the administrative region also said armed men had attacked the two camps and continued to hold them.
He said there had been deaths but could not provide a toll.
Almou Ag Mohamed, a spokesman for the Coordination of Azawad Movements, an alliance of armed separatist groups dominated by Tuaregs, claimed the attack.
"We attacked and took control of the two military camps in the town of Lere this Sunday," he told AFP. "The camps are under our control. We shot down an army plane."
Officials have said the assailants have not yet been formally identified.
The successionist groups in 2012 launched a rebellion before signing a peace agreement with the state in 2015. But that accord is now generally considered moribund.
This month has seen a resumption of hostilities by the groups.
On Tuesday, the groups launched an offensive against army positions in the garrison town of Bourem, which the military said it had repelled.
The two sides provided contradictory reports of events, but both reported dozens of deaths.
The renewed military activity by the separatists has coincided with a series of attacks attributed mainly to the al-Qaida-linked jihadist alliance Support Group for Islam and Muslims (GSIM).
In August, GSIM announced it was declaring "war in the Timbuktu region."
In a separate incident on Sunday, two soldiers were killed and one injured in an ambush near the village of Akor in western Mali, the intelligence services said.
That attack took place on a supply mission returning from the town of Guire, it said, adding that four attackers had also been killed.
On Saturday, junta leader Assimi Goita signed a mutual defense pact with his Nigerien and Burkinabe counterparts establishing a military alliance and pledging to assist one another in the event of an attack on their sovereignty or territorial integrity.