U.N. officials say nine peacekeepers have been wounded when their convoy was hit by a roadside bomb in northern Mali.

Oliver Salgado, spokesman for the U.N. mission in Mali, said the violence took place Sunday along the road between the northern towns of Aguel'hoc and Tessalit.

Salgado said the wounded peacekeepers had been evacuated for medical treatment.

Such attacks have become increasingly common in northern Mali, where a number of Islamic extremist groups are active. Earlier this month, an attack on a U.N. camp in Timbuktu killed seven people.

The U.N. mission has been working to stabilize Mali, where jihadists seized control of the north in 2012 before a French-led military operation scattered them the following year. U.N. convoys and the Malian military have been frequent targets.