BAGHDAD, Iraq (CNN) -- The Iraqi government said it will file criminal charges against employees of security firm Blackwater USA who were involved a gun battle in Baghdad in which civilians were killed, an Iraqi Interior Ministry official said Sunday.

Members of a private security company pose on the rooftop of a house in Baghdad earlier this month.

The official said the charges will come within a week.

It is not clear how Iraqi courts will attempt to bring the contractors to trial.

The Iraqi government has no authority over private security firms contracted by the U.S. government, according to a July report from the Congressional Research Service.

Order 17 from the Coalition Provisional Authority appears to shield security contractors from Iraqi laws.

It states, "Contractors shall be immune from Iraqi legal process with respect to acts performed by them pursuant to the terms and conditions of a Contract or any sub-contract thereto."

The Iraqi government claims the private contractors, who were guarding a U.S. diplomatic convoy, killed as many as 20 civilians.

Iraqi officials, who claim the shootings were unprovoked, dispute Blackwater's claim that the guards were responding to an attack and said on Saturday they had a videotape showing the Blackwater guards opened fire without provocation.

The incident prompted the Iraqi government to call for Blackwater's expulsion from the country and sparked anger among Iraqis. Watch a report on Blackwater's response to the allegations »

U.S. State Department spokesman Sean McCormack said earlier this week the Blackwater employees involved in the incident were still in Iraq.

Word of Iraq's intent to file charges came as no surprise. One day after the shooting, Iraqi Prime Minister Nuri al-Maliki said his government would punish those responsible.

On Sunday, Rear Adm. Mark Fox, Communications Division chief for Multi-National Force-Iraq, and Dr. Tahseen Sheikhly, civilian spokesman for the Baghdad Security Operation, refused to comment on Iraq's plan to file charges.

But they gave some details on a joint U.S.-Iraqi commission that would examine issues of security and safety in the aftermath of the shooting.

The commission -- to be co-chaired by Iraqi Minister of Defense Abd al Qadir and Patricia A. Butenis, the charge d'affaires of the U.S. Embassy -- will receive the results of both a State Department investigation and the separate Iraqi investigation in the next few days, Fox and Sheikhly said.

Blackwater contractors are part of the estimated 25,000-plus employees of private security firms who are working in Iraq, guarding diplomats, reconstruction workers and government officials. As many as 200 security contractors have been killed in Iraq, according to U.S. congressional reports.

Blackwater resumed its normal operations of providing security to U.S. civilian authorities in Iraq on Friday after a hiatus sparked by concerns among Iraqi and U.S. government officials over last weekend's shootings.

Sheikhly said the Iraqi government has allowed Blackwater to again operate in the streets of Iraq because, otherwise, U.S. troops would have to be pulled from the field to provide security.

Meanwhile, 19 bodies were found by Iraqi police in Baghdad over the weekend, an Interior Ministry official told CNN on Sunday. The total number of bodies reported to be found in the capital this month is 251. E-mail to a friend

CNN's Mohammed Tawfeeq contributed to this report.

All About Blackwater USA • Iraq