Suspected jihadists killed a policeman in a rare attack in southern Mali, hoisting their black flag at the local military base, just days before the country's main Tuareg-led rebel movement is expected to sign a peace deal.

The west African nation remains divided among rival armed factions, plagued by drug trafficking and infiltrated by jihadist groups, but attacks outside the unrest-riven north of the country remain unusual.

A minister said "cowardly terrorists" killed a warrant officer in Misseni, near Mali's border with Ivory Coast, while a local councillor said "around 30 jihadists" briefly occupied the town's army camp.

The councillor said the militants arrived at 2:00 am (0200 GMT), adding: "I heard gunshots in the Misseni military camp. The jihadists were shouting 'Allahu Akbar (God is greatest).'

"They took control of the military camp where they put up their black flag."

The militants opened fire on local policemen, killing the officer before escaping, according to the councillor, who spoke on condition of anonymity.

A Malian security source confirmed the policeman's death, adding that "the terrorist jihadists led an organised attack".

"They probably came from Ivory Coast because Misseni is 20 kilometres (12 miles) from the Ivorian border," the source added.

"They covered part of the distance in a vehicle, and another part on motorcycles and on foot."

A separate source at the town's police headquarters said two Malian army vehicles and police motorcycles were set alight.

A local military source told AFP the army had sent back-up from regional capital Sikasso.

A witness in Misseni said the militants escaped at around 5:00 am, leaving behind a copy of the Koran and a piece of paper on which was written Ansar Dine, a jihadist group that is active in northern Mali and linked to Al-Qaeda.

- Struggle for stability -

Mali's desert north has struggled to maintain stability since the west African nation gained independence in 1960.

The country descended into chaos in 2012 when an insurgency by Tuareg rebels led to a coup in the capital Bamako. Jihadists linked to Al-Qaeda then overpowered the Tuareg to seize control of the north.

A French-led military operation launched in January 2013 drove the extremists out of the region's towns and cities.

But the country remains deeply divided, with the Tuareg and Arab populations of the north accusing sub-Saharan ethnic groups in the more prosperous south of marginalising them.

Tuareg rebels and Islamist militants remain active throughout the north, a vast area the size of France, but attacks outside of the region are rare.

Al-Murabitoun, an Islamist militia led by notorious Algerian jihadist commander Mokhtar Belmokhtar, claimed responsibility for an attack against Westerners in Bamako on March 7.

Three Malians, a French national and a Belgian were killed as militants stormed a nightclub that was popular with the capital's expatriate community.

The group also carried out a suicide attack on April 15 against the Nigerian contingent of the UN mission in Mali, killing two civilians.

Hopes for peace in Mali were boosted last week when the main Tuareg-led rebel movement announced it would sign an agreement to end the conflict in the west African nation on June 20.

The Coordination of Azawad Movements (CMA) initialled the deal alongside the Malian government in May but was holding out on a final deal until guarantees were made about the representation of northern populations in any future security force.

The CMA on Wednesday, however, claimed the signing of the agreement could be in jeopardy after accusing pro-government militias of carrying out arbitrary arrests and looting in northeast Mali.

Mali's jihadist groups have been sidelined during the peace process however, and were not involved in UN-brokered talks to formulate the accord.