At least 23 civilians have been killed in attacks on villages in troubled central Mali by armed men, a local mayor and a Malian security source said on Monday.

"During Sunday, and overnight, in the villages of Bidi, Sankoro and Saran, armed men attacked civilians, killing 23 of them," Cheick Harouna Sankare, mayor of the neighbouring town of Ouenkoro, told AFP. 

"The situation is serious, the army needs to act to reassure the population," he said, adding that an emergency meeting had been called.

The death toll was confirmed by a security source in Mali.

Separately, 11 people died when an explosive device blew up near the central town of Koro close to the border with Burkina Faso, a local official told AFP on condition of anonymity.

Ethnic tensions in the centre of the country have surged since a jihadist group led by preacher Amadou Koufa emerged in 2015. 

The group recruit mainly from among the Fulani -- primarily cattle breeders and traders -- and they have clashed with the Dogon and Bambara -- traditionally sedentary farmers who have formed their own self-defence militias.

There has been a wave of mass killings this year, including the massacre of 41 people in two ethnic Dogon villages on June 17, according to a UN count.

And in March, 160 Fulani were killed in an attack on a village by suspected rival militiamen.

Unrest in the central region coincides with an ongoing jihadist campaign that the Mali government is struggling to contain despite military help from France and the United Nations.