Friday's attack took place between the northern cities of Gao and Ansongo, they said.

"The jihadists ambushed a civilian convoy escorted by Malian soldiers and Wagner mercenaries. At least 10 people have been killed and that's a very provisional toll," a local official told AFP, requesting anonymity.

"There are civilians and soldiers among the dead."

On Saturday, a medical source said many of the dead and wounded had been transferred to Gao, the main city in northern Mali.

A source from a transport trade union said: "According to a transporter who managed to escape, jihadists ambushed the convoy's escort and opened fire on everyone at random to cause the largest number of victims."

Another local official told AFP: "The Malian soldiers and Wagner (mercenaries) were in around 10 vehicles protecting a convoy of 22 minibuses with civilian passengers, six large buses and eight lorries."

"At least five lorries were destroyed by Islamic State (IS) jihadists."

IS has not claimed responsibility for the attack.

The Malian army has not officially commented on the reported attack..

"We control the situation on the ground between Ansongo and Gao," a military source said.

The route between Ansongo and Gao has seen several attacks in recent months blamed on jihadists or bandits who rob civilians.

Mali has faced serious security problems since 2012 linked to violence both by groups linked to Al-Qaeda and IS and by local criminal gangs.

Its military rulers have broken ties with former colonial ruler France and turned politically and militarily towards Russia.