WASHINGTON, April 24: Prominent human rights groups have urged Congress to launch an independent and bipartisan probe to determine the roles of senior US leaders in prison abuses in Iraq. One of them — Human Rights Watch — named President George W. Bush, Defence Secretary Donald H. Rumsfeld and former CIA director George J. Tenet among the people it wants investigated.

The group said that an independent commission could compel evidence that the government has continued to conceal, including the directives reportedly signed by President Bush authorizing the CIA to establish secret detention facilities and facilitating the ‘rendition’ of suspects to brutal regimes.

Rendition is the practice of transporting prisoners to a third country where they can be tortured for extracting information.

The Human Rights Watch reported that since the Sept 11 attacks, US agents have secretly transported up to 150 detainees to countries that practise torture.

The American Civil Liberties Union, which after a lawsuit secured tens of thousands of pages of army documents relating to abuse investigations, denounced the findings of an internal army investigation that has cleared four of the five senior army officers suspected of abusing detainees in Abu Ghraib and elsewhere.

“The president must appoint a special counsel — who is not beholden by rank or party and who is able to look up the military chain of command. We need to make accountable those who are putting our own soldiers at risk of torture and who tarred America’s image in the world community,” said ACLU executive director Anthony D. Romero.

The Human Rights Watch and Amnesty International also supported the demand. All three groups said that similarities in alleged abuses in Iraq, Afghanistan and Cuba cannot be ignored as coincidences.

“The total exoneration of Lt-Gen Ricardo S. Sanchez runs counter to what previous investigations have strongly suggested, which is that there was a failure at the command level and not just aberrant behaviour by individual guards and interrogators,” said Alistair Hodgett, a spokesman for Amnesty International USA.

Gen Sanchez supervised massive US detention facilities and intelligence-gathering operations in Iraq.

“(His exoneration) does seem to confirm that only an independent investigation would be capable of setting out who bears responsibility and what their punishment should be,” said Mr Hodgett.

On Capitol Hill, Republican Senator John W. Warner, who heads the Senate’s Armed Services Committee, vowed to hold more hearings into prison abuses until he was satisfied that proper people were held accountable.

Last week, Democratic Senator John D. Rockefeller IV, vice-chairman of the Senate’s Intelligence Committee, urged a separate congressional review of how the CIA detained and interrogated prisoners.

In its report “Getting away with Torture? Command Responsibility for the US abuse of Detainees”, the Human Rights Watch presents substantial evidence warranting criminal investigations of Mr Rumsfeld and M. Tenet, as well as Gen Sanchez and Gen Geoffrey Miller, the former commander of the prison camp at Guantanamo Bay, Cuba.

The Human Rights Watch demanded that Secretary Rumsfeld should be investigated for potential liability in war crimes and torture by US troops in Afghanistan, Iraq and Guantanamo.