The Nigerian president has declared a state of emergency in parts of northern Nigeria plagued by a violent Islamist insurgency, and said he would shut any borders with other nations in those areas covered by the decree.
Goodluck Jonathan said the closure of borders in the affected areas was an interim measure designed to address the current security challenges.
The decree means parts of Nigeria's border with Niger, Chad and Cameroon will be sealed until further notice.
He added that his chief of defence staff had been instructed to take other "appropriate" measures, including setting up a special counter-terrorism force.
Militants from Boko Haram, a radical Islamist sect, set off a series of bombs across Nigeria on Christmas Day, including one that killed at least 37 people and wounded 57.
The blasts raised fears that Boko Haram, a movement styled on the Taliban and whose name means "Western education is forbidden", is trying to ignite sectarian strife in Nigeria, Africa's most populous nation and top oil producer.
The local government areas listed included parts of Niger State, Borno and Yobe, all of which have become infiltrated with Boko Haram militants.
