The islamist militant group Boko Haram is threatening to confront Nigerian soldiers after the decision by the president to declare a state of emergency in parts of the north.
Heavily armed troops and tanks have been patrolling the streets in areas where the insurgents are concentrated. At least 40 people were killed in a series of bomb attacks on Christmas Day across the country.
President Goodluck Jonathan has plegded to crush the militants. He visited the region on Saturday amid tight security. He offered condolences to families of the victims, promising extra measures and a determination to “weed out” Boko Haram from Nigerian society.
His visit included a church on the edge of the capital Abuja, where 37 people died and 57 were injured in one of the attacks.