The bodies of two U.S. soldiers reported captured last week have been recovered, and an Iraqi official said Tuesday the men were "killed in a barbaric way."

In this undated photo released Monday, June 19, 2006, by the Menchaca family, Army Pfc. Kristian Menchaca is shown. [AP]

Al-Qaida in Iraq claimed responsibility for killing the soldiers, and said the successor to slain terror leader Abu Musab al-Zarqawi had "slaughtered" them, according to a Web statement that could not be authenticated.

The language in the statement suggested the men had been beheaded.

U.S. Maj. Gen. William Caldwell confirmed that the remains, found late Monday by American troops, were believed to be those of Pfc. Kristian Menchaca, 23, of Houston, and Pfc. Thomas L. Tucker, 25, of Madras, Ore.

Caldwell said the cause of death was "undeterminable at this point," and that DNA tests would be conducted to confirm the identities.

The two disappeared after a deadly insurgent attack Friday at a checkpoint by a Euphrates River canal south of Baghdad. The checkpoint was in the Sunni Arab region known as the "Triangle of Death" because of frequent ambushes there of U.S. soldiers and Iraqi troops.

The director of the Iraqi defense military's operation room, Maj. Gen. Abdul-Aziz Mohammed, said the bodies showed signs of having been tortured. "With great regret, they were killed in a barbaric way," he said.