Factbox: What's in WikiLeaks' Iraq war logs?

WASHINGTON (Reuters) - Whistle-blowing website WikiLeaks on Friday released nearly 400,000 classified U.S. military files chronicling the Iraq war from 2004 through 2009, the largest leak of its kind in U.S. military history.

The documents themselves are known at the Pentagon as 'SIGACTs,' raw field reports chronicling "Significant Action" in the conflict as seen by U.S. forces on the ground in Iraq.

According to an initial review of the documents and reports by other media that have had access to them for at least 10 weeks, the broad themes from the "Iraq war log" attracting the most attention are:

PRISONER ABUSE

* U.S. authorities face accusations of failing to investigate hundreds of reports of abuse of Iraqi prisoners by Iraqi police and soldiers, including cases of rape and even murder that are detailed in the logs. WikiLeaks says there are also cases of abuse of prisoners in U.S. custody, but media given advance access say those cases pale in comparison.

CIVILIAN DEATHS

* WikiLeaks said the reports detailed 109,032 deaths in Iraq, composed of 66,081 'civilians,' 23,984 'enemy' (those labeled as insurgents); 15,196 'host nation' (Iraqi government forces) and 3,771 'friendly' (coalition forces). More than 15,000 civilians died in previously unknown incidents, Britain's Guardian reported.

* In February 2007, an Apache helicopter killed two Iraqis suspected of firing mortars even though they were trying to surrender. A military lawyer is quoted in one file saying, "They can not surrender to aircraft and are still valid targets." Other cases involved civilian killings at checkpoints.

IRANIAN INFLUENCE

* Military intelligence reports released by WikiLeaks detail previously well-known U.S. concerns that Iranian agents had trained, armed and directed militants in Iraq.

* In one document posted by The New York Times, the U.S. military warned that a militia commander believed to be behind the deaths of U.S. troops and the kidnapping of Iraqi government officials was trained by Iran's Islamic Revolutionary Guard Corps.

BLACKWATER

* Britain's Bureau of Investigative Journalism says it found documents detailing new cases of alleged wrongful killings of civilians involving a firm previously known as Blackwater. Blackwater, which has now changed its name to Xe Services, saw its reputation badly damaged by a 2007 incident in which its security guards were involved in a shooting that killed 14 civilians.

IRAN DETENTION OF U.S. HIKERS

* Documents in the WikiLeaks file also show that U.S. officials privately believed the three American hikers detained in Iraq last year were on the Iraqi side of the border, not in Iran as Tehran contends. Iran is still holding two of them and the document says Iranian leadership hoped to benefit from the incident by focusing the nation "on a perceived external threat rather than internal dissension."

(Reporting by Phil Stewart; Editing by Eric Walsh)