BAMAKO (Reuters) - A Malian pro-government militia has killed eight Islamist fighters in a gunbattle in northern Mali, two security sources said on Sunday.

Clashes between the militia and the Macina Liberation Front erupted on Saturday in Gourma-Rharous village, in the Timbuktu region of Mali which has long been plagued by Islamist militants, a military source and one from the militia told Reuters by telephone.

They had no details of how the clashes started.

Mali's government and various separatist groups signed a peace deal last year but it has failed to prevent periodic violence in northern Mali by Islamist militants, who have also staged assaults on high profile targets in the capital Bamako, Burkina Faso and Ivory Coast.

United Nations Secretary-General Ban Ki-moon has asked the Security Council to add just over 2,500 peacekeepers to the U.N. peacekeeping mission in Mali.

Al Qaeda in the Islamic Maghreb (AQIM) has claimed an attack on two U.N. sites in northern Mali at the end of last month, in which a peacekeeper from China and three civilians were killed and over a dozen others wounded.

French forces intervened in 2013 to drive back Islamist fighters that had hijacked the Tuareg uprising to seize Mali's desert north in 2012, but it has since proved difficult to prevent Islamists staging deadly attacks.

(Reporting by Tiemoko Diallo; Writing by Tim Cocks; Editing by Ros Russell)