NINE people accused of carrying out a deadly attack in north-central Nigeria have been arraigned before a federal court in connection with the deaths of more than 150 people.

The defendants are being charged with 57 counts of terrorism and could be sentenced to death or life imprisonment if convicted. They pleaded “not guilty” on Monday to the charges relating to the attack on Yelewata, a community in the Guma district of Nigeria’s Benue state, in June last year.

Presidential spokesman Kamarudeen Ogundele said in a statement on Sunday that the Nigerian government had undertaken a “painstaking investigation and collaboration by government agencies.”

He added: “The office of the attorney general of the federation and minister of justice wishes to assure Nigerians that justice will be ensured in the matter to send a strong signal to the enemies of the country, acting under any disguise.”

Nigeria is in the grip of a complex security crisis, with an insurgency by Islamist militants in the north-east and a surge in kidnappings for ransom by gunmen across the north-west and north-central regions over the recent months.

Attacks such as the one in Yelewata are common in Nigeria’s northern region, where local herders and farmers often clash over limited access to land and water.