More than 60 people were killed by a twin suicide bomb attack at a camp in Dikwa town, northern Nigeria for people displaced by an insurgency of the jihadist Boko Haram group, a military and emergency official said on Wednesday.

The attack took place some 85 km (50 miles) outside the capital of Borno state, center of the seven-year insurgency, they said.

It took place on Tuesday, but a breakdown in the telephone system had prevented the information being made public earlier, reports Reuters.

The attackers reportedly detonated their explosives while the refugees were queuing to collect food rations.