One soldier is shown kicking a wounded, cuffed Iraqi detainee and another striking a detainee with a rifle butt, according to US military documents.
The videos were described in 1200 pages of documents released by the US army on Friday in response to a lawsuit by the American Civil Liberties Union, which is seeking information on prisoner abuse in Iraq.
Previously, the US military had been providing the documents to the ACLU, which in turn has made them public, but on Friday provided copies to the news media as well.
US army officials said the documents summarized 13 investigations, none of which resulted in abuse charges.
A number were closed due to insufficient evidence.
The US army, which says it is committed to finding and correcting problems in prison operations, has so far released the results of 129 investigations to the ACLU.
Jameel Jaffer, an attorney with the ACLU, called the US army documents "further evidence that abuse of detainees was widespread in Iraq and Afghanistan.
"In some small number of cases, low-ranking soldiers have been punished. In light of the hundreds of abuses we now know to have taken place, it's increasingly difficult to understand why no senior official, civilian or military, has been held accountable."
The ACLU, along with Human Rights First, sued Defence Secretary Donald Rumsfeld this week in connection with alleged abuses of prisoners.
The Ramadi Madness video was a compilation of recordings taken of the actions of B Company, 1st Battalion, 124th Infantry Regiment, a unit of the Florida National Guard that was in Iraq in 2003 and early 2004, according to the investigation documents. The company is based in West Palm Beach.
The video led to disciplinary action, the company's commander Major Joseph Lyon told the South Florida Sun-Sentinel newspaper.
In light of the hundreds of abuses we now know to have taken place, it's increasingly difficult to understand why no senior official, civilian or military, has been
He would not specify who was disciplined or the extent of the discipline.
"The video is definitely inappropriate," Lyon said. "However, we were still in a very tight situation, a stressful situation. ... You can think you're going to act a certain way, but until you're in that certain situation, you don't know."
The investigation began after a civilian public-affairs officer in Florida saw some of the video while other soldiers were watching it.
The video itself was not released. Investigation documents describe efforts to prevent it from being leaked to the news media.
The investigation found that the video "contained footage of inappropriate rather than criminal behaviour", according to a summary of the investigation, dated 28 December 2004. Ramadi is a city in Iraq.
According to investigators, one part of the video showed an Iraqi lying on the ground, handcuffed and moaning, when a soldier kicked him.
The prisoner had been shot through the abdomen because he allegedly raised a gun towards American soldiers during a raid, US army investigators said.
Investigators found one soldier, whose name was blacked out from the documents, who acknowledged he looked like the one in the video, although his face was obscured.
The video "contained footage of inappropriate rather than criminal behaviour"
A summary of the investigation,
dated 28 December 2004
The soldier said he did not remember kicking the Iraqi.
Several US soldiers said they did not believe the kick constituted an assault.
The fate of the detainee is unclear.
Another section of the video appeared to show a soldier hitting a cuffed Iraqi in the head with a rifle butt during an interrogation, according to the civilian who first reported it.
One US soldier told interrogators that this was a staged image, and the Iraqi was not actually hit with the rifle.
The soldier said the Iraqi, a juvenile, had been detained for allegedly throwing rocks at a US military convoy and was later released.
A third showed one soldier manipulating a dead Iraqi, shot while trying to run a checkpoint in a truck, to make it appear the man waved to the camera.
The soldier said he only positioned the body so other US personnel could remove it. He also alleged there was a missile in the truck.
Other investigations included in the US army documents involve other units in Iraq.
One case involves an Iraqi who said he was beaten against a Bradley infantry carrier by two soldiers after being detained. Medics said he had a seizure.
The case was closed for insufficient evidence.
Another investigation concerns allegations of rape and other abuses in Iraq by US soldiers of the 3rd Infantry Division, which were recounted in a Playboy article.
The investigation could not validate the allegations in the article.
Most abuse cases were closed
due to 'insufficient evidence'
A former US soldier was charged with making a false official statement after alleging some of his comrades stole from Iraqis at vehicle checkpoints in Iraq.
A civilian with the organisation searching for weapons of mass destruction alleged a US military prison guard at Baghdad International Airport forced a detainee to drink his own urine. The investigation could not prove this happened.Investigations into shootings in what US forces say were riots at prisons, found that in each case the shooting was justified.