Nigeria announced a state of emergency in the northeast of the country on Saturday, as at least 50 people were killed during clashes between ethnic groups further south.
In a response to the multiple Christmas Day bomb attacks by radical Islamic sect Boko Haram, the borders with neighbouring Cameroon, Chad and Niger have been shut.
The defence ministry will also set up a special counter-terrorism force as part of emergency measures.
Saturday’s violence took place in the southeastern state of Ebonyi, where there has been a long running rivalry between the Ezza and Ezilo people.
Disputes over land are common in Nigeria because the majority of the population are subsistence farmers.
President Goodluck Jonathan has been criticised for his slow response to the Christmas Day bombings.
The largest blast killed 37 people and wounded 57 at a church on the outskirts of the capital Abuja.