WASHINGTON - Some 90,000 leaked U.S. military records amount to a blow-by-blow account of six years of the Afghanistan war, including unreported incidents of Afghan civilian killings as well as covert operations against Taliban figures.

The online whistle-blower organization Wikileaks was planning to post the documents on its website Sunday. The New York Times and London's Guardian newspaper, as well as the German weekly Der Spiegel, were given early access to the documents.

The documents -- including classified cables and assessments between military officers and diplomats -- describe U.S. fears that ally Pakistan's intelligence service was actually aiding the insurgency.

The Times said the documents suggest Pakistan "allows representatives of its spy service to meet directly with the Taliban in secret strategy sessions to organize networks of militant groups that fight against American soldiers in Afghanistan, and even hatch plots to assassinate Afghan leaders."

The Guardian said the documents show "how a secret 'black' unit of special forces hunts down Taliban leaders for kill or capture without trial" and "how the U.S. covered up evidence that the Taliban has acquired deadly surface-to-air missiles."

One U.S. official said the Obama administration was aware of the impending document release and had already told Pakistani and Afghan officials what to expect, in order to head off some of the more embarrassing revelations.

Another U.S. official said it may take days to comb through all the documents to see what they mean to the U.S. war effort and determine their potential damage to national security. That official added that the U.S. isn't certain who the source of the leaked documents is.

Both officials spoke on condition of anonymity in order to comment on the release of classified material.