The two-week operation on the islands of Lake Chad netted the largest number of arrests, said Colonel Onyema Nwachukwu, adding that the operation included air and ground offensives.
The military said many Boko Haram insurgents were killed, but it did not give details.
Among those arrested were 167 Boko Haram fighters, 67 women and 173 children. The women and children will be handed over to authorities of displacement camps after investigations, the military said.
Another 57 insurgents were arrested during a separate operation in another part of the troubled region.
Boko Haram has been blamed for more than 20,000 deaths during its eight-year insurgency, which has spilled over into neighbouring countries and created a vast humanitarian crisis with millions displaced and starving.
Human rights groups have expressed concern about the large number of women and children who have been arrested in the fight against Boko Haram, saying most of those detained have been picked up at random and without reasonable suspicion.
In an effort relieve overcrowded military detention facilities, Nigeria’s government in October began the trials of more than 1,600 suspected Boko Haram members, behind closed doors at a military barracks.
It was the largest mass trial in the Islamic extremist group’s history.
While Nigeria’s President Muhammadu Buhari declared that the extremist group had been “crushed” late last year, the group’s leader Abubakar Shekau remains elusive.
Boko Haram has also carried out a growing number of deadly suicide bombings and other attacks in recent months. Many have been carried out by women or children who were abducted and indoctrinated.
Earlier this week, dozens of Nigerian state governors approved the transfer of $1bn (£750m) to aid the federal government’s fight against Boko Haram, signalling that the announcements of victory over the extremists had come too soon.
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