BAGHDAD: At least 40 inmates, including prisoners with suspected links to the Islamic State, have escaped a prison in eastern Iraq early after overpowering guards, Iraqi officials said.

Dozens of inmates and at least six guards were killed in the incident, which took place at the Khalis prison in Diyala province. In January, pro-government forces took control of the province from the Islamic State as part of a military offensive to win back the vast territory in Iraq that the extremist group seized in June.

In a sign of the chaos that continues to plague areas that have fallen under government control, officials gave conflicting reports of the number of people killed. Citing unnamed prison and police officials, the Reuters new agency reported that 50 inmates and 12 guards were killed.

But Saad Maan, an Interior Ministry spokesman, said by telephone that 30 prisoners and six guards were confirmed killed in the incident, which started when an inmate seized an unspecified weapon from a guard and went on a shooting spree.

“Forty people escaped, and nine are Daesh members,” he said, using the Arabic name for the Islamic State.

Hakim Al-Zamily, head of Parliament’s security committee, said 80 inmates with terrorism charges managed to escape. At least 30 inmates and six guards were killed, he said, describing the incident as a “major security lapse.”

Diyala, a province with Sunnis and Shiites, is under the control of pro-government Shiite militias, which played a significant role in driving out Islamic State militants from the area. The presence of the militias has caused tensions to soar, especially among Sunni residents, who accuse the groups of carrying out sectarian-motivated attacks and killings.

Raad Al-Dahliky, a Sunni parliamentarian from Diyala, accused the Shiite militias of playing a role in the prison break and called for a government investigation.

Last month, Kataib Hezbollah, a Shiite militia, announced in a statement that it broke into a police prison in north Baghdad and freed five of the group’s members.

“The prison had several prominent members from the militias who appear to have escaped, and so it seems that these militias played a role in the escape,” he said. “The prison is in the center of the city, and it’s completely surrounded and protected by the militias, so it’s not like this could have happened easily.”