Updated

Nigerian military officials say they killed about 70 Boko Haram fighters when the Islamic extremists attacked the northeastern town of Bama Monday morning.

The officials, who insisted on anonymity because they were not authorized to speak to the press, said militants arrived Monday morning in armored tanks and trucks and tried to take over the town.

Muhammed Gava, a spokesman for the anti-Boko Haram vigilante movement, said most of Bama's residents fled to Maiduguri.

Sani Usman, an army spokesman, said Monday the curfew in Maiduguri has been extended from 7 p.m. to 6 a.m.

Amnesty International said last month that more than 4,000 people — mostly civilians — have been killed this year in the Nigerian conflict, including in Boko Haram attacks and in responses by the security forces.