Iraqi officials say they have found the bodies of 14 policemen who went missing shortly after leaving their base north of the capital, Baghdad.
Several of the men were shown in police uniform
The bodies were found in the Diyala province, close to where the policemen disappeared on Thursday, officials say.
Earlier, an al-Qaeda-linked group claimed it had kidnapped 18 interior ministry employees in the same area.
This was retaliation for the alleged rape of a Sunni woman by members of the mainly Shia police, it said.
The statement could not be verified. The government denies a rape occurred.
The government is currently pushing a new security plan that will see mainly-Shia police units being deployed in predominantly Sunni districts.
Sunni politicians have accused the police of perpetrating a series of human rights abuses on their community and of turning a blind eye to attacks on them by Shia militants.
In other developments:
- At least 10 people have died in a bomb attack in Baghdad's Shia stronghold of Sadr City, officials say
- Two players from the Ramadi football club are shot dead by gunmen as they take part in a training session, Iraqi police say
- The United States military in Iraq says it killed eight suspected insurgents in a raid in Salman Pak, south-east of Baghdad.
Interior ministry official Brig Gen Abdel Karim Khalaf said the 14 bodies were found near the city of Baquba, 50km north of Baghdad, according to the Associated Press news agency.
He blamed al-Qaeda for the killings, pledging that the Iraqi authorities would "chase those who assassinated" the policemen.
The policemen disappeared on Thursday, shortly after leaving their base to go on leave.
The kidnap claim, by the Islamic State of Iraq, was posted on a number of Islamist websites on Friday.
The statement was accompanied by the pictures of 18 men blindfolded and with hands tied behind their backs, seven of them wearing police uniforms.
"This blessed operation is a response to crimes carried out by those infidels in their fight against the Sunnis," it said.
"The latest of the crimes committed by these traitors was to rape our sister in religion."
The group later said it killed the hostages, after the Iraqi government had ignored its demands to hand over officials accused of the rape and to release all Sunni women held in Iraqi prisons within 24 hours.
The woman has said in an emotional interview with al-Jazeera TV that she was raped after a wrongful arrest for helping insurgents.
Last week, Iraqi Prime Minister Nouri Maliki ordered an investigation into the allegations, but the three officers under suspicion were cleared.
Mr Maliki, who is himself Shia, also released a copy of a US medical report saying no rape had taken place.
But the New York Times reported that a nurse, speaking on condition of anonymity, said she had treated the woman at a clinic in her neighbourhood of Amil and had seen signs of sexual and physical assault.