At least 23 civilians have been killed in attacks on villages in troubled central Mopti region of 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 neighboring 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 to the AFP by a security source in Mali.

Local media outlets reported that the attackers were dressed as members of the Dogon group.

Sankara said the attackers headed to the Bidi village after the attack in Saran but some 300 residents had already been evacuated, Anadolu Agency reported.

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 center of the country have surged since an extremist 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-defense 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 U.N. 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 terrorist campaign that the Mali government is struggling to contain despite 4,000 troops deployed by France under Operation Barkhane and the 15,000-strong Multidimensional Integrated Stabilization Mission in Mali (MINUSMA) peacekeeping force of the U.N.

Separately, unidentified gunmen have killed 16 soldiers in an attack on a military camp in western Niger near the border with Mali, local residents and security sources said on Tuesday.

The raid occurred on Monday afternoon near the town of Inates, where militants are active, and in the same region where an ambush by Daesh's West African branch killed 28 soldiers in May.

Bandits on motorbikes carried out the assault with "two car bombs," a source told AFP on condition of anonymity.

The volatile region is a major base where Nigerien soldiers are trained to serve in the MINUSMA region.

Niger hosts the African Union summit from July 6-9 less than 200 kilometers (125 miles) away in the capital Niamey. In the run-up, the European Union has been training Nigerien forces to respond to militant attacks.

Zakari Insa, the brother of one of the soldiers killed in Monday's attack, and Souley Marou, a local villager, both said 16 soldiers had died.

Two security sources confirmed the death toll, and one of them said about a dozen vehicles had been stolen. Terrorists have previously launched attacks using vehicles stolen in previous raids.

An army spokesman could not immediately be reached for comment.

Security has deteriorated in recent months across West Africa's Sahel region, a semi-arid strip of land south of the Sahara.

Militants loyal to Adnan Abu Waleed al-Sahrawi, the leader of Daesh in the Greater Sahara, operate along Mali's border with Burkina Faso and Niger.

Various insurgent groups operate in Niger's west and north, while Nigeria's Boko Haram is present in the southeast.

The country is part of the so-called G5 Sahel group set up to manage a coordinated response to the terrorist insurgency.

The U.S. has a big base for drones in the northern city of Agadez and Niger recently gave the Americans permission to arm their drones.

The French also have a military base near Niamey airport and another at Madama in the north.

Earlier this month, 18 Daesh terrorists were killed in a joint operation by U.S., French and Niger troops in the same area.

In 2017, they killed four members of U.S. Special Forces and four Nigerien soldiers in an ambush near the village of Tongo Tongo.