An estimated 80 people have been killed in communal violence in Nigeria since Dec. 31, police and officials said Tuesday.

The clashes are mostly between Muslim cattle herders and Christian farmers over the use of land in parts of the Middle Belt — the country's most diverse region.

On Tuesday, President Muhammadu Buhari ordered an increased police presence in the Benue state, Agence France-Presse reported.

Similar clashes have taken place across central states in the country, polarizing Nigerians along ethnic and religious lines, and challenging Buhari's promise to bring security and stability to the country — a central pledge of his 2015 campaign.

In November, at least 30 members of the cattle herding community, including children, were killed in a clash in the northeastern state of Adamawa.