Two versions emerged regarding how the breakout happened. According to Brig. Gen. Saad Maan, the prison break began when prisoners were able to seize a weapon from a guard and clashed with other guards.

ISIS, however, said it was responsible for the prison break, saying its fighters on the outside coordinated with its members who were inside the facility.

According to a statement posted on several prominent ISIS accounts on Twitter, fighters on the outside blew up military and security vehicles near the prison with improvised bombs. At the same time, ISIS members imprisoned on the inside took control of a weapons storage room and started the gunfight.

In all, 40 prisoners escaped, including nine who had been in custody on terrorism charges, police spokesman Brig. Gen. Ghalib Atiya told CNN.

Five prison guards and 30 inmates were killed in the clashes, Maan said.

Elsewhere in Diyala province, 11 people were killed and 15 wounded in twin explosions in the town of Baladrouz late Friday, Atiya added.

The two car bombs exploded in a busy commercial street in the town north of Baghdad.

Meanwhile, four people were killed on Saturday when a powerful car bomb exploded in Baghdad, near Shiite Muslims preparing for an annual pilgrimage, police officials said.

Twenty-six people were wounded in the blast in the capital city's Karrada district, according to the officials. It happened near the site where people were getting ready to set off next week for a traditional pilgrimage to commemorate the death of Imam Moussa al-Kadhim, one of 12 revered imams in Shiite Islam.

It was not immediately clear who was responsible for the violence.

While Baghdad hasn't been hit as hard by ISIS as other parts of the country, it has seen plenty of bloodshed in recent years — much of it tied to persisting tensions between Sunni and Shiite Muslims.

Shiite pilgrims have often been among the victims; thousands have been killed or wounded over the past decade.