At least 67 people are believed dead after gunmen overtake a town in Nigeria’s northeast region on Friday, following four other bloody attacks, the Associated Press reports.

Boko Haram, a radical Muslim sect, has claimed responsibility for the attacks. The group is  believed to have ties to al-Qaeda's North Africa branch. The attacks mark the group's largest and most coordinated yet, with more promised to come.

The overnight attacks centered in Damaturu, the capital of Yobe state, Nigerian Red Cross official Ibrahim Bulama told the Associated Press. The violence first began on Friday when suicide bombers detonated a car bomb outside a building used as a military post. Gunmen proceeded to pillage the town, blowing up a bank and attacking several police stations and some churches. Bloodshed persisted throughout the night as gunmen raided the village of Potiskum, leaving at least two people dead, witnesses said.

The attacks around Damaturu followed four separate bombings on Friday in Maiduguri, about 80 miles (130 kilometers) east.

In August, Boko Haram claimed responsibility for a suicide car bombing at the United Nations headquarters that killed 24 people and left another 116 wounded. The group threatens to overpower Nigeria’s weak central government, seeking to put strict Shariah law in place in the oil-rich nation.

The most recent attacks in Nigeria’s predominately Muslim northern region come ahead of celebrations of Eid al-Adha, or the feast of sacrifice.