At least six police officers and 30 prisoners were killed late Friday during an assault in a prison in eastern Iraq as dozens of inmates escaped, spokesman for the country’s interior ministry said Saturday. Forty inmates reportedly held on terrorism charges escaped the prison after overpowering the guards.

The incident took place at the Khalis prison in Al-Khalis, Diyala province, about 50 miles northeast of Baghdad. Brig. Gen. Saad Maan Ibrahim said Saturday that a fight broke out among the inmates and when the guards went to investigate they were attacked and had their weapons taken, the Associated Press reported. Two provincial police officials and a medical official stated that 51 inmates and 12 policemen were killed, while more than 200 inmates escaped the prison, which holds about 300 inmates charged with acts of terrorism, AP reported, but the numbers could not be immediately confirmed.

"The inmates started fighting among themselves which drew the attention of the police guards who went to break up the fight," a police source, who spoke on the condition of anonymity, said, according to Reuters. "Then the prisoners attacked them, stripped them of their weapons and started a riot while also managing to capture the armory of the prison."

Clashes between the inmates and security forces reportedly continued for more than four hours following which the situation was taken under control. The incident also injured 15 policemen, Xinhua News reported, citing a source.

Prison breaks are reportedly frequent in Iraq, where the government faces multiple security challenges.