More than 30 people have been killed in clashes in the desert of northern Mali, the army and Tuareg rebels said, just days before the start of internationally-brokered peace talks.

An army source told the Reuters news agency on Sunday that 37 people had been killed in clashes which began on Friday in the northern desert area between Gao and Kidal. The army blamed the violence on infighting between rebels.

Peace talks between Mali government officials and Tuareg rebels are due to start in Algeria on Wednesday, the first meeting since clashes took place in the Tuareg stronghold of Kidal in May in which some 50 Malian soldiers were killed.

The army source said those killed in the most recent clashes were from the main Tuareg separatist group National Movement for the Liberation of Azawad (MNLA) and a group of northern Malian Arabs called Arab Movement of Azawad (MAA).

MNLA spokesman Mohamed Ag Attaye, however, said in a statement that 35 were killed from the Malian army and other "militias" and blamed government forces for starting the attack.

In past incidents, both sides have played down the casualties they sustained.

France dispatched troops to Mali last year to halt the advance by rebels. The former colonial power currently has 1,700 troops in Mali and said on Sunday it was reorganising its forces in Mali and surrounding countries into a single regional body.

"It's a regional operation to ensure the security of the area and prevent jihadist groups from emerging again," French Defence Minister Jean-Yves Le Drian said on Europe 1 radio.

The United Nations has also deployed a peacekeeping force in Mali which operates separately from French troops.

UN peacekeeping chief Herve Ladsous said on Friday he was "concerned by certain armed groups' violation of the ceasefire agreements signed with Bamako on May 23."

France, as well as Mali's northern neighbour Algeria and the West Africa regional bloc ECOWAS are pushing the warring sides to hold talks that could end decades of Tuareg uprisings in Mali's desert north.

In addition to deep distrust between the armed groups and Bamako, tensions between the separatists is a challenge for mediators. On several occasions, disagreements have led to open conflict between them.

Mali's separatist movements are demanding greater autonomy for northern Mali, which they term Azawad.