Suspected jihadists killed 51 civilians in northern Mali and killed 12 troops in an ambush in neighbouring Burkina Faso, the authorities said today, highlighting the security crisis gripping the two fragile states.

"Terrorists" yesterday invaded the villages of Karou, Ouatagouna and Daoutegeft near Mali's border with Niger, a military officer said, using a term officials use to designate jihadists.

"(They) massacred everyone," the source said, speaking on condition of anonymity.

A document by the local prefecture, seen by AFP, said 51 people had been killed in the coordinated attacks, homes had been looted and cattle stolen.

A local official, who also asked not to be identified for security reasons, said "20 civilians were massacred in Karou. Fourteen civilians were killed in Ouatagouna, and other civilians were killed in the hamlet of Daoutegeft".

The assailants arrived on motorbike, taking the villagers by surprise, he said.

An official at a fourth village said his locality had also come under attack.

An army unit has been sent to provide help, a military officer said, but a source in a Malian NGO said communications with the remote area were poor after jihadists had attacked telecoms sites.

Mali, a landlocked and impoverished state in the heart of the West Africa's Sahel region, has been battling a jihadist insurgency since 2012.

The crisis began with unrest in the north of the country that spread to Mali's ethnically volatile centre and then to neighbouring Niger and Burkina Faso.

Armed groups linked to al-Qaeda and the so-called Islamic State group are steering the campaign today.

Thousands of civilians and troops have died and hundreds of thousands of people have fled their homes.

Mali has suffered two coups since August last year, and on 20 July military leader Colonel Assimi Goita survived an attempted assassination at a mosque in Bamako.