Lagos - The military said on Saturday it had killed 10 insurgents and arrested 65 more as part of an offensive meant to wrest back control of parts of its remote northeast from Boko Haram.
President Goodluck Jonathan has been accused of not taking seriously enough the violence in the north.
A spokesman for Defence Headquarters said the military had seized stockpiles of weapons including rocket-propelled grenades, guns and ammunition from areas around Maiduguri, the main city in the northeast.
"The Special Forces have apprehended 65 persons confirmed to be terrorists as they made an attempt to infiltrate Maiduguri while fleeing from various camps now under attack," Brigadier-General Chris Olukolade said in a statement.
He added that in the Gamburu ward of Maiduguri, where the Boko Haram uprising began, "a total of 10 suspected terrorists were confirmed dead."
"The area is being combed to fish out any of the surviving insurgents," he said.
The military said it had imposed a 24-hour curfew over large parts of Maiduguri - an older curfew had only applied at night.
The operation against Boko Haram began after President Jonathan declared a state of emergency on Tuesday in the states of Borno, Yobe and Adamawa.
Nigerian forces used jets and attack helicopters to bombard militant camps in the northeast on Friday, their biggest offensive since Boko Haram began an insurgency almost four years ago to try to create a breakaway Islamist state.
Boko Haram re-armed
Nigerian forces are trying to regain territory controlled by well-armed militants in remote semi-deserts in the area around Lake Chad, along the borders with Cameroon, Chad and Niger.
But the United States and human rights groups have raised concerns about the military's heavy handed approach, which they say has led to hundreds of civilian deaths.
The military said on Friday it had destroyed a number of camps in dry forests around Borno state, the epicentre of the insurgency and a region that once hosted one of West Africa's oldest medieval Islamic empires prospering from trade routes linking its interior with the Mediterranean cost.
The move has proved popular with Nigerians keen for one of its most violent episodes since the 1967-70 Biafran war to end.
"The action by the presidency was timely. Our state is being turned into a cemetery by these terrorists," Kwamoti Laori, a barrister and deputy speaker of Adamawa state's legislature, told Reuters.
But it remains to be seen whether the military can crush an insurgency that has proved adept at melting away under pressure and then resurfacing when the heat is off.
Nigerian authorities thought Boko Haram was finished after a 2009 crackdown left 800 people dead, including the sect's founder, a cleric called Mohammed Yusuf. Instead, it transformed into something much more deadly, developing sophisticated bomb technology and linking up with al-Qaeda's north African wing.