JOHANNESBURG, South Africa - Explosions and fighting broke out early Friday in the troubled northern Nigerian city of Maiduguri, as dozens of insurgents attacked a military barracks holding rebel detainees, according to government officials.
It was unclear how many prisoners had been freed in the attack on the Giwa barracks, which left dozens dead, most of them insurgents, Nigerian authorities said.
Borno state police chief Lawal Tanko told the state-owned News Agency of Nigeria that local media reports of an additional attack on the university were erroneous.
"What happened was that the insurgents passed through a river channel behind the university to launch the attack on the barracks," he said.
No group claimed responsibility for the fighting, which bore hallmarks of previous raids on jails and military barracks by the Al Qaeda-linked terror group Boko Haram, which has employed the tactic to free hundreds of its partisans.
The latest skirmish lasted several hours. Nigerian military spokesman Brig. Gen. Chris Olukolade, said the military had the situation under control. He added that most of the casualties were militants, an assertion that could not be independently checked.
Olukolade described the attack as a bid by terrorists "to boost their depleted stock of fighters." Nigerian authorities in recent weeks have said that Boko Haram is close to defeat, a claim it has made before.
"The attack has been successfully repelled with heavy human casualty on the terrorists [side]," he said in a statement.
The attackers reportedly managed to penetrate the detention facility and free some detainees, but many of those were killed as they tried to escape, according to local media reports.
Olukolade said four soldiers were injured.
Gruesome photographs of more than a dozen bodies, allegedly from the barracks, surfaced on Nigerian social media Friday. The images could not be verified.
Local media reported that Nigerian jets attacked the fleeing insurgents.
Boko Haram has killed thousands of people in northern Nigeria in recent years, including many civilians, in its bid to establish an Islamic state across all of Nigeria, a country divided between Muslims and Christians. Several states in the predominantly Muslim north have adopted sharia law systems.
Earlier this month Boko Haram launched an attack on a crowded market in Maiduguri, killing at least 50 people.
The group, which is opposed to secular education, has targeted schools and students. Late last month an attack authorities blamed on the group killed dozens of students in a dormitory at a school near Damaturu in northeastern Yobe state. Some had their throats cut as they tried to flee.
The group has criticized the Nigerian authorities' approach to the crisis, saying its scatter-shot approach after terror attacks has led to civilian casualties and cemented local support for Boko Haram. The "horrific conditions" in Giwa barracks has led to hundreds of detainee deaths by dehydration, illness and beatings, the group has said.