An army spokesman in Mali says three soldiers have been killed and one injured when their vehicle hit a land mine.

Col. Abdoulaye Sidibe said the incident occurred Wednesday in the northern Timbuktu region. It comes one day after armed men ambushed the convoy of a local official west of Timbuktu, killing one soldier and injuring two others.

On Monday, two vehicles carrying Chadian peacekeepers hit land mines in the northern Kidal region, and one of the soldiers later died of his injuries.

Islamic extremists took control of northern Mali in 2012, prompting a French-led intervention that drove them from stronghold cities and towns in 2013. But north and central Mali remain unstable, and attacks by al-Qaida in the Islamic Maghreb and allied groups against peacekeepers and security forces are common.