Updated

Nigeria's president is declaring a state of emergency in parts of the West African nation after a slew of recent attacks blamed on a radical Muslim sect.

President Goodluck Jonathan on Saturday declared the state of emergency in four states and ordered the closure of international borders near the affected areas. They include parts of Borno state, where the northeastern city of Maiduguri is a stronghold for the Boko Haram sect.

He says: "What began as sectarian crises in the northeastern parts of the country has gradually evolved into terrorist activities."

He directed top security officials to set up a special counterterrorism unit.

The sect claimed responsibility for Christmas Day attacks that have now left at least 42 people dead.