Human Rights Watch said it's not seen the results from a Defense Ministry investigation into the Jan. 25 shooting of Fallujah protesters at the hands by military troops.
Joe Stork, deputy director of Middle East programs, said the government needs to show that it's serious about the investigation.
"Iraqi authorities seem to think that announcing an investigation is all that's required when security forces kill protesters," he said in a statement.
Human Rights Watch said Iraqi forces fired on protesters after the troops hit with stones. The rights group said nine protesters were killed and another 45 were injured.
Political violence in Iraq flared after U.S. forces left the country in December 2011. A protest movement against Iraqi Prime Minister Nouri al-Maliki has emerged in Anbar, a predominately Sunni province.
Fallujah was the former seat of the insurgency during the early stages of the war last decade. Local elections are scheduled for April.
The Voice of Iraq news agency reports five policemen were killed Thursday in a bombing in Mosul in northern Iraq.