Al-Jazeera on Friday released what it called "startling new information" from US documents obtained by WikiLeaks, alleging state-sanctioned Iraqi torture and the killing of hundreds of civilians at US military checkpoints.
It said that the major findings included a US military cover-up of Iraqi state-sanctioned torture and "hundreds" of civilians deaths at manned American checkpoints after the US-led invasion of 2003 that ousted Saddam Hussein.
The Qatar-based satellite broadcaster also said the leaked papers, dating from January 1, 2004 to December 31, 2009, show the United States kept a death count throughout the war, despite US denials.
US Secretary of State Hillary Clinton condemned "in the most clear terms" the leaks of any documents putting Americans at risk.
Speaking to reporters in Washington, she declined to discuss the specifics of the WikiLeaks disclosures.
"But I do have a strong opinion that we should condemn in the most clear terms the disclosure of any information by individuals and or organisations which puts the lives of United States and its partners' servicemembers and civilians at risk," she said.
Earlier on Friday, the WikiLeaks website promised a "major announcement" in Europe on Saturday, in a message on its Twitter feed.
Al-Jazeera's English channel was to broadcast a series of programmes from 2100 GMT on Friday, it said in a statement sent to AFP, "that reveal startling new information about the operations of US forces during the Iraq War."
It said the programmes are based on files from WikiLeaks "who gained access to over 400,000 documents regarding the War in Iraq making it the largest document leak in US history.
"The secret materials are more than four times larger then Wikileak's Afghanistan files," the broadcaster said in a statement issued in English.
WikiLeaks infuriated the Pentagon in July by publishing 77,000 classified US military documents on the war in Afghanistan.
"Although one of the stated aims of the Iraq War was to close down Saddam Hussein's torture chambers, the Wikileaks documents show many cases of torture and abuse of Iraqi prisoners by Iraqi police and soldiers," Al-Jazeera said.
"In addition, the documents reveal the US knew about the state sanctioned torture but ordered its troops not to intervene."
Al-Jazeera said the leaked documents also provide new information on the killing of civilians by US private security firm Blackwater.
"The secret US files reveal new cases of Blackwater (a company now known as XE) opening fire on civilians. No charges were ever brought," the statement said.
The broadcaster's Arabic service reported that the civilian death toll in Iraq was "much higher than officially announced."
Also included in the papers obtained by WikiLeaks was information on what the station's statement in English called the "secret involvement" of Iran in financing Shiite militias in Iraq.
"The files detail Iran's secret war in Iraq and discuss Iran's Revolutionary Guard acting as an alleged supplier of arms to Shia insurgents," Al-Jazeera said.
It said the papers also included US Army reports about Iraqi Prime Minister Nuri al-Maliki "and allegations of his association with death squads" in Iraq.
The Pentagon warned on Friday that releasing secret military documents could endanger US troops and Iraqi civilians.
"By disclosing such sensitive information, WikiLeaks continues to put at risk the lives of our troops, their coalition partners and those Iraqis and Afghans working with us," Pentagon press secretary Geoff Morrell said.
He said the documents were "essentially snapshots of events, both tragic and mundane, and do not tell the whole story.
"That said, the period covered by these reports has been well-chronicled in news stories, books and films and the release of these field reports does not bring new understanding to Iraq's past," Morrell added.
The Pentagon said last week that a 120-strong taskforce was scouring an Iraq war database to prepare for the potential fallout from the release of secret military reports.
It appealed to the media to avoid facilitating the leak of documents regarding Iraq.
NATO chief Anders Fogh Rasmussen also said on Friday that the lives of soldiers and civilians could be placed in peril if WikiLeaks released confidential documents.
