WASHINGTON (REUTERS) - The US State Department is increasing security at some American embassies in anticipation of the public release of a long-awaited Senate report detailing the Central Intelligence Agency's (CIA's) use of harsh interrogation techniques, US officials said on Tuesday.

The officials, who spoke on condition of anonymity, said the additional security measures reflected concerns that the report could prompt protests in countries where the CIA operated secret prisons that were used to conduct interrogations.

Human rights activists and some US politicians have labelled as "torture" some of the physically stressful interrogation techniques, such as simulated drowning, that were authorised under then-president George W. Bush.

For security reasons, State Department officials declined to specify how or where US embassies were being fortified in anticipation of the release of the Senate Intelligence Committee report.

One official said the Obama administration was concerned that the report's publication could ignite a "tinder box" in Middle Eastern countries and also frighten some foreign security agencies into scaling back cooperation with their US counterparts.

According to unclassified documents and extensive news reports, sites where the spy agency secretly imprisoned detainees as part of its now-defunct "Rendition/Detention/Interrogation" programme included Poland, Romania, Thailand, and Afghanistan, and the US military base at Guantanamo Bay, Cuba.

While countries involved in the programme were exposed in news stories several years ago, the report's publication could rekindle anger, particularly in the Muslim world, at US practices that were pursued during Mr Bush's "war on terror."

Most, if not all, references in the report to the former locations of secret CIA prisons were redacted by the Obama administration in the process of preparing a declassified version of the report for public release, officials said.

McClatchy Newspapers reported on Monday that the original, uncensored version of the report used pseudonyms when referring to countries where the agency operated secret prisons and that the White House and Central Intelligence Agency redacted these pseudonyms, rather than actual country names.

An official familiar with both versions of the report said that publishing even the pseudonyms would provide readers with too many clues as to where CIA interrogations took place.

It is unclear when the Senate committee will release a declassified version of the document

Senator Dianne Feinstein, who chairs the panel, and other members of the committee's Democratic majority have complained that the Administration's redactions are excessive.

Release of the roughly 600-page document, a summary of a much longer committee narrative that will remain secret indefinitely, is unlikely this week, officials said.

On Friday, the office of director of national intelligence James Clapper said 85 per cent of the report had been declassified by the Administration, and half of the redactions were to the report's footnotes.

Ms Feinstein and other Democrats are pressing for some of the redacted information to be restored.

An official said Republicans on the intelligence committee, who largely boycotted the five-year investigation that produced the report and have drafted their own critique of it, are comfortable with the current redactions.