One of the diplomatic cables recently released by Wikileaks offers new evidence that American troops massacred 10 handcuffed Iraqi civilians and destroyed the evidence with an airstrike -- charges that the U.S. military has categorically denied.

An unclassified cable from Philip Alston, the U.N.'s special rapporteur on extrajudicial, summary or arbitrary executions, challenges the military's official account of what happened during a raid on the Iraqi town of Ishaqi. Alston wrote to a U.S. embassy to charge that American troops intentionally killed civilians, an allegation that was made by Iraqis at the scene and supported by reporting from multiple news organizations. The U.S. military has ignored his requests for more information, as has the Iraqi government.

The tragedy is that this elaborate system of communications is in place but the [U.N.] Human Rights Council does nothing to follow up when states ignore issues raised with them, Alston wrote to McClatchy.

In March of 2006, Iraq was engulfed by sectarian bloodletting. In the midst of the soaring violence U.S. forces, backed by helicopter bunships, raided a house in Ishaqi, a town about 80 miles northwest of Baghdad that is in an area then considered to be highly dangerous. For about 25 minutes, the troops found themselves in an intense firefight.

From there, the accounts diverge. U.S. military spokesmen said that an al-Qaida in Iraq operative was captured from the house, and that the ferocity of the fight had reduced the structure to rubble. A subsequent military investigation exonerated troops of any wrongdoing. the investigation acknowleged that the raid caused as many as nine civilian fatalities but attributed the deaths to the house collapsing

But the Joint Coordination Center in Tikrit, a regional security center set up with American military assistance and staffed by U.S.-trained Iraqi police officers, maintained that the 11 civilians killed -- four of them women and five of them children younger than the age of five -- were purposefully executed.

The American forces gathered the family members in one room and executed 11 persons, including five children, four women and two men. Then they bombed the house, burned three vehicles and killed their animals, the Joint Coordination Center's report said.

Alston's cable supports those claims, that autopsies conducted on the civilians determined that they had been handcuffed and shot in the head. Alston also disputed the idea that the house was destroyed in the firefight, maintaining that it was still standing until the U.S. called in an airtstrike.

Troops entered the house, handcuffed all residents and executed all of them, Alston wrote. After the initial MNF [Multi-National Force] intervention, a U.S. air raid ensued that destroyed the house.

McClatchy noted that the cable also backed up what neighbors and the doctor who performed the autopsies told Knight-Ridder -- which is now owned by McClatchy -- immediately after the incident. The BBC also released a video that depicts dead bodies at the sight with what appear to be bullet wounds.

Col. John Gregory, a spokesman for the Pentagon, told The New York Times that the cable contained nothing new we haven't already looked into here.