Mali's separatist rebels say they killed 30 army soldiers in an attack on an army convoy.

Mohamed Elmaouloud Ramadane, spokesman for the Coordination of Azawad Movements, a coalition of separatist groups, said they killed 30 army soldiers when they attacked an army patrol about 40 kilometers (25 miles) southwest of Timbuktu, on the road to Goundam.

The toll could not be immediately confirmed by independent sources.

Radhia Achouri, a spokesman for the United Nations mission in Mali, confirmed the attack but did not give a casualty figure. Achouri said civilians were caught in the crossfire.

Col. Diarran Kone, spokesman for Mali's defense forces said they could not confirm a casualty toll.

The violence threatens a peace deal meant to be signed on May. 15.