Authorities in Nigeria have imposed a 24-hour curfew in the main northeastern city of Maiduguri after suspected Islamic militants attacked an air force base and army barracks.
Residents in Maiduguri say hundreds of suspected Boko Haram militants besieged the installations early Monday.
A reporter for VOA who is in the city says buildings at the army barracks were burned to the ground and burnt-out cars littered the grass.
A Defense Ministry spokesman said 24 insurgents died in a shootout with soldiers, but he did not say whether or not there were any civilian causalities.
The spokesman said two helicopters and three military aircraft were damaged in the attack.
Flights at Maiduguri airport, which is near the air force base, were temporarily disrupted by the violence.
The curfew in Maiduguri is the first the Borno state government has imposed since 2009.
Borno is one of the areas where President Goodluck Jonathan declared a state of emergency in May as part of efforts to defeat the Islamist Boko Haram.
Nigeria's military says it has killed scores of militants and destroyed several of the group's camps, but that attacks against civilians continue.
Boko Haram is blamed for thousands of deaths in attacks since 2009.
Boko Haram is believed to want to impose strict Islamic law across Nigeria's Muslim-majority north. The fight against the group is complicated by uncertainty about its structure and leadership, and questions about whether criminals are using the group's name as cover for their activities.
Rights groups have also accused the military of using indiscriminate and heavy-handed violence in its efforts to crush the group, and causing hundreds of civilian deaths.