Newly disclosed military documents show a higher Iraqi death toll than previously acknowledged during the years of Iraq's sectarian war that raged after the U.S.-led invasion of the country in 2003.

The information released Friday by the WikiLeaks website reveals about 15,000 previously unreported deaths, according to one independent research group that analyzed the numbers.

WikiLeaks website founder Julian Assange held a news conference in London on Saturday. (Lennart Preiss/Associated Press)

Iraq Body Count, a British-based anti-war group, said that would raise the total from about 107,000 civilians to more than 122,000.

The activists who published the classified documents talked about the U.S. military logs at a news conference in London on Saturday.

"We have seen that there are approximately 15,000 never previously documented or known cases of civilians who have been killed by violence in Iraq," WikiLeaks editor in chief Julian Assange said. Assange said his group released this latest deluge of reports to reveal hidden truths about the war.

"In our release of these 400,000 documents about the Iraq war, the intimate detail of that war from the U.S. perspective, we hope to correct some of that attack on the truth that occurred before the war, during the war and which has continued on since the war officially concluded," he said.

"This disclosure is about the truth," Assange said, adding the documents show the war has been "a bloodbath on every corner."

'No further investigation'

Most of the allegations of abuse centre on Iraqi authorities and their acts of injustice and violence against Iraqi citizens. But the reports also indicate that American troops often failed to follow up on credible evidence that Iraqi forces mistreated, tortured and killed captives.

Cases of abuse were sent up the chain of command in the U.S. military, but many of the reports were then stamped, "No further investigation."

"One example is of a little child who was tortured with an electric drill on her legs by a group of Iraqis who wanted her family to pay ransom money for her," CBC's Anne MacMillan reported from London.

"Another incident involved a man who was taken prisoner by Iraqi soldiers and kept in an underground bunker, suspended from the ceiling, beaten with electric cables and was so badly injured he had to be treated by U.S. medics. They wrote a report. Again it was stamped, 'No further investigation.'"

Pentagon spokesman Col. Dave Lapan, speaking from Arlington, Va., said much of the information released is lacking in context.

"They are first-hand reports, done at the very tactical level by troops in the field. So they're essentially witness statements, if you will, initial observations, and they could be inaccurate.

"But they also are snapshots in time for that particular incident and they don't include followup of what may have come in the hours, days and weeks later," he said.

The 391,831 documents date from the start of 2004 to the beginning of this year. They provide a ground-level view of the war written mostly by officers in the field.

The dry reports, full of military jargon and acronyms, were meant to catalogue "significant actions" over six years of U.S. and allied military presence in Iraq.

The Pentagon has previously declined to confirm the authenticity of WikiLeaks-released records. But it has never indicated that any past WikiLeaks releases were inaccurate.

WikiLeaks said Saturday it will soon publish 15,000 additional secret documents from the war in Afghanistan. The group previously published some 77,000 U.S. intelligence reports about the Afghan war.

With files from The Associated Press