"Returning from a successful military operation against the jihadists' main base in Dialloube, where ten terrorists were neutralised, an army vehicle drove over a mine, killing four soldiers," said a military source at the defence ministry.

A foreign military source confirmed the deaths, adding that two other soldiers were seriously injured.

Jihadists have ramped up their activities in central Mali in recent months, targeting domestic and foreign forces in violence once confined to the restive north.

Four UN peacekeepers were killed and four were wounded last week when a mine exploded under their vehicle in central Mali.

During a visit to the region earlier this week Mali's Prime Minister Boubeye Maiga assured that ramped up military operations were beginning to bear fruit.

Islamic extremists linked to Al-Qaeda took control of the desert north of Mali in early 2012, but were largely driven out in a French-led military operation launched in January 2013.

In June 2015, Mali's government signed a peace agreement with coalitions of armed groups. But the jihadists remain active, and large tracts of the country are lawless.