WASHINGTON, Dec. 12 (Xinhua) -- A bipartisan U.S. Senate report has concluded that former Defense Secretary Donald H. Rumsfeld was to blame for detainee abuses in the so-called "war on terror," the Washington Post said Friday.

    The report, endorsed by Democrats and Republicans on the U.S. Senate Armed Services Committee, said decisions made by Rumsfeld were a "direct cause" of the abuses, and other Bush administration officials were responsible for creating a legal climate that contributed to inhumane treatment, according to the newspaper.

    It is seen as the most forceful denunciation to date of the role that Rumsfeld and other top officials played in the prisoner abuse scandals in the past five years.

    The report also challenged assertions by senior Bush administration officials that the most egregious cases of prisoner mistreatment were isolated incidents of appalling conduct by U.S. troops.

    "The abuse of detainees at Abu Ghraib of Iraq in late 2003 was not simply the result of a few soldiers acting on their own," the report said.

    Instead, a series of high-level decisions by the Bush administration "conveyed the message that physical pressures and degradation were appropriate treatment for detainees in U.S. military custody," the report added.

    The report aimed its harshest criticism at Rumsfeld's decision in December 2002 to authorize the use of aggressive interrogation techniques at the U.S. detention facility in Guantanamo Bay, Cuba.

    The report also criticized President George W. Bush, though less harshly.

    In particular, it cited a presidential memorandum signed on February 7, 2002, which denied detainees captured in Afghanistan the protection of the Geneva Convention, which bans abusive treatment of prisoners of war.

    Bush's decision to bypass an international law that had been observed by U.S. troops for decades sent a message that "impacted the treatment of detainees in U.S. custody," it said.

    The Senate report represents the culmination of an 18-month investigation by the committee's staff.

    It is the latest in a series of investigations started after photographs surfaced in April 2004 of prisoners at the U.S.-run Abu Ghraib prison in Iraq being stripped of their clothes, piled in pyramids and strapped to what appeared to be electrical wires.