An Islamic militant group has claimed on its website to have killed 11 Iraqi national guardsmen it kidnapped near Baghdad last week.
Militant website shows pictures of the men they claim to have killed
The Army of Ansar al-Sunna showed still pictures of the men - some held at gunpoint - which they say were killed for associating with US "crusaders".
In a statement, the group said it had beheaded one man and shot the other 10.
An Iraqi defence ministry spokesman said it had no information that 11 national guardsmen were missing.
The claim came days after a group led by Abu Musab al-Zarqawi admitted the kidnap and murder of 49 army recruits.
The Arabic al-Jazeera television station reported that Ansar al-Sunna's website boasted of kidnapping the men along the road between Baghdad and the town of Hilla.
The group was believed to have been seized on 21 October.
"After questioning them it became evident that this unit's duty was to protect occupying American crusader forces," a statement read.
"We slaughtered one of them and shot dead the rest."
One of the images on the group's website reportedly showed the beheaded man with his head placed on his back.
Other photographs are said to have pictured the 10 other murdered hostages with their hands tied behind their backs.
A voiceover on the video, identified by subtitle as the head of the group, urged the Iraqi security forces not to co-operate with the US-led occupation, the Associated Press reported.
"A call to the army and police: repent to God... Abandon your weapons and go home and beware of supporting the apostate Crusaders or their followers, the Iraqi government, or you will find only death," the voice said.
The latest killings came just days after the massacre of 49 unarmed army recruits in the east of Iraq.
A group loyal to Jordanian-born militant Abu Musab al-Zarqawi and pledging allegiance to al-Qaeda claimed responsibility.
The Army of Ansar al-Sunna, which also claims loyalty to Zarqawi, has a track record of kidnap and murder in post-war Iraq.
Earlier this year the group seized and killed 12 Nepalese hostages, and it recently killed a Turkish truck driver it said was ferrying supplies for US forces.
Members have also killed several Iraqi Kurds branded as "spies".
In other developments:
- Iraqi interim Prime Minister Iyad Allawi urged the rebel-held city of Falluja to seize what may be its last chance to avert a military assault
- A little-known insurgent group said it had kidnapped a Polish woman and demanded that Poland withdraw troops from Iraq, al-Jazeera TV reported
- A senior Iraqi diplomat was shot dead while returning to his home in Baghdad, according to the Iraqi foreign ministry
- A reporter working for independent Iraqi TV channel, Al-Sharqiya, was shot dead with her translator while driving in Baghdad, reports said
- Ukrainian soldiers stationed in Iraq came under mortar fire at a checkpoint in the centre of the country