Geneva — United Nations agencies are alarmed that insurgent groups clashing with Nigerian security forces and attacking civilians in Borno State are targeting humanitarian groups and NGO aid workers trying to help locally-besieged civilians and the 65,000 people who are on the run.

Jens Laerke, Geneva spokesman for the United Nations Office for the Coordination of Humanitarian Affairs, also known as OCHA, says that at least five NGO offices and vehicles and equipment belonging to the groups have been destroyed.

At least eight civilians have been killed and a dozen injured in northeast Nigeria, said the UN, noting that the armed groups' actions are severely disrupting humanitarian work.

"OCHA continues to receive alarming reports of the humanitarian consequences of the clashes between insurgent groups and the Nigerian Armed Forces in Damasak in Borno State, and that non-state armed groups are targeting humanitarian assets and facilities," Laerke said at a UN press conference in Geneva on Friday.

"Recently, these groups have also been conducting house to house searches, reportedly looking for civilians identified as aid workers," he said. He did not explicitly name the groups carrying out the attacks in an area where Boko Haram has been active.

Laerke said, "We identify them as non-state armed groups. There are more than one. So, I don't want to point specifically because it's not always clear to us who they are. They don't necessarily identify themselves, but there are several.

The UN Refugee Agency, UNHCR, said it is deeply concerned over up to 65,000 Nigerians who are on the move following a series of attacks by armed groups on Damasak.

"Assailants looted and burned down private homes, warehouses of humanitarian agencies, a police station, a clinic, and also a UNHCR facility," UNHCR spokesman Babar Baloch said, noting that the latest attack was the third in a week.

He said that In the reported attack on Wednesday 14 April, "up to 80 per cent of the town's population —which includes the local community and internally displaced people as well – had been forced to flee."

Violence in the Lake Chad region Basin has uprooted 3.3 million people, and more than 300,000 are Nigerian refugees; more than half of them are hosted in the Niger and Diffa regions.

The situation is "extremely critical", said Laerke, noting that if the attacks continue in Damasak, "it will be impossible, maybe for longer periods, for us to deliver aid to people who desperately need it."

UNHCR said that its staff relocated out of Damasak temporarily during the week.