At least 29 people were killed and 50 wounded in an attack on a prison in Jalalabad city of Nangarhar province of Afghanistan on Monday, Tolonews reported. A shopping plaza was also attacked. The Islamic State terrorist organisation claimed responsibility.

Among the dead were prisoners, civilians, prison guards and Afghan security personnel, according to Attaullah Khogyani, a spokesperson for the governor of Nangarhar province, Shah Mahmood Miakhel, Al Jazeera reported.

Nangarhar police chief Emal Niazi said that both the prison and the shopping plaza have been cleared of attackers, following an 18-hour long battle. Eight attackers were killed, he said.

The attack began when a suicide bomber detonated a vehicle full of explosives at the entrance gate of the prison, at 6.44 pm local time (7.44 pm Indian Standard Time) on Sunday. The attack began on the last day of the ceasefire between the Taliban and the Afghanistan government, but the extremist group said it was not responsible.

The purpose of the attack is not clear, but hundreds of prisoners at the jail are members of the Islamic State group, AP reported. Khogyani said about 1,000 escaped prisoners had been caught, but it is unclear if any more are at large.

In May, gunmen dressed in military fatigues attacked a hospital in Afghanistan’s Kabul city, killing 14 persons, including two newborn babies. The attackers were killed after a five-hour encounter with security forces.