Two US soldiers missing in Iraq since Friday have been found dead south of Baghdad, the US military has said.
Kristian Menchaca (left) and Thomas Tucker have been missing
The bodies were found in the Yusifiya area on Monday. An Iraqi defence ministry spokesman said the bodies had shown signs of torture.
An insurgent group linked to al-Qaeda in Iraq, which claimed it abducted the men, has now said that it killed them.
The missing men have been named as Kristian Menchaca and Thomas Tucker, both from the 101st Airborne Division.
Another US soldier, David Babineau, was killed in the attack on the checkpoint.
US military spokesman in Iraq, Maj Gen William Caldwell, said the bodies were found late on Monday by US troops.
"We have recovered what we believe are the remains of our two missing soldiers. They will be taken back to the United States for positive verification."
He said the cause of death was "undeterminable at this point".
But Iraqi defence ministry spokesman Gen Abdul Aziz Mohammed said: "We found they had been tortured in a barbaric fashion."
A US statement said that the bodies had been booby-trapped.
It said 8,000 coalition and Iraqi forces had been carrying out a massive search for the missing men, and that one US soldier died and another 12 were injured in clashes during the search.
Relatives of the men have already reacted with grief and anger.
Ken MacKenzie, uncle of Kristian Menchaca, said on US television: "Because the US government did not have a plan in place, my nephew has paid for it with his life."
At least three people were killed in one bomb blast in Baghdad
An internet statement posted by the Mujahideen Shura Council - a grouping of insurgents that includes al-Qaeda in Iraq - said it had abducted the men and slit their throats.
The posting, which cannot be independently confirmed, said the new leader of al-Qaeda in Iraq - Abu Hamza al-Muhajir - had been "favoured by God" in being allowed to carry out a Sharia law tribunal death sentence.
The former leader of al-Qaeda in Iraq, Abu Musab al-Zarqawi, was killed in a US air strike near Baquba on 7 June.
Gen Caldwell said on Tuesday US forces had killed Zarqawi's "right-hand man" in a raid in Yusifiya on Friday, near where the US troops were abducted.
The general said Iraqi Mansur Suleiman al-Mashhadani was "a key leader in al-Qaeda" and could have succeeded Zarqawi.
The US also said it had killed 15 "terrorists" in an "extremely long firefight" in Bushahin, north of Baquba.
The US military said its forces came under attack from gunmen on a roof and around nearby buildings. After the firefight, it said, various weapons and explosives were found.
However, angry local people said the dead were all innocent poultry workers.
Meanwhile, violence continued around Iraq despite Zarqawi's death and a new security clampdown involving tens of thousands of Iraqi and US troops in Baghdad:
- At least three people are killed in a car bomb in a market in Sadr City, eastern Baghdad
- Two more people are killed and 28 hurt in an explosion at a clothes market in central Baghdad
- Elsewhere, at least one elderly woman was killed along with a suicide bomber who blew himself up inside a home for the elderly in the southern city of Basra.