Yusuf Ali | Cii News and Agencies, Pic: AFP | 03 October 2012

At least 25 people have been killed in Nigeria’s northeastern town of Mubi in the Adamawa state. Most of the victims are thought to be college students.

Earlier reports suggested that a lecturer estimated more than 40 students had been killed but there was no official comment.

Speaking on condition of anonymity to the BBC, a local said men in military uniform asked the students to line up and then say their names. Some of the students were then shot dead and others stabbed with knives and their bodies left in lines outside the buildings.

It is not clear why some were killed and others spared, nor was there a motive as some of those killed were Muslims and others Christian.

The man said that students were now leaving the town, many with tree branches over their cars, which is a traditional sign of neutrality in Nigeria.

The authorities have imposed an indefinite curfew in the town and ordered residents to stay indoors.

The university has been temporarily shut down.

Last week, the Nigerian military carried out an operation in Mubi and arrested dozens of people over suspected links to Boko Haram.

Boko Haram came to prominence in 2009, staging an uprising in the state capital, Maiduguri.

Yushua Shuaib, spokesman for the National Emergency Management Agency, confirmed the attack to the Reuters news agency but had no details on casualties.

Boko Haram has not yet commented on the Mubi attacks.