Bamako (AFP) - Seven UN peacekeepers have been wounded in an explosion in northeastern Mali, military sources from the force told AFP on Monday.

The cause of Sunday's blast was not immediately clear but the soldiers were in Tabankort, a powder-keg town in the foothills of the Ifoghas mountains and the scene of deadly violence between rival militias.

"Seven UN peacekeepers were wounded in an explosion, the cause of which is not yet known. I can't say yet whether it was an attack or an accident," the source from the UN's MINUSMA mission said.

"Four of the peacekeepers were seriously injured. They were all in Tabankort. They were taken to Gao by the French military's Operation Barkhane."

Another MINUSMA source in Gao, the largest city in northern Mali, said the force was considering the possibility that "people were able to get into the UN camp in Tabankort", without giving further details.

International and Malian troops frequently come under attack from jihadists in Mali's restive northern desert.

A peacekeeper with the UN force was killed by gunmen on January 18, a day after two Malian soldiers were killed in the central town of Tenenkou.

On January 5, 11 Malian soldiers were killed during an assault on the Nampala garrison near the border with Mauritania.

The vast, sparsely populated region fell to Islamist groups in 2012 before the extremists were ousted by Operation Serval, a French-led military intervention.

Serval has since evolved into France's Operation Barkhane, which has 3,000 troops battling jihadist groups around the Sahel region stretching the width of Africa beneath the Sahara.

Tabankort is part of a large swathe of desert which is the cradle of an ethnic Tuareg movement that wants independence for the homeland it calls "Azawad", and from which several rebellions have been launched since the 1960s.

The town, between the cities of Gao and Kidal, is controlled by pro-government militias, however, which have been clashing over recent weeks with armed rebels.

Various pro and anti-government factions are in talks with the administration being hosted by Algeria.