President Bush should appoint an independent commission to investigate military abuse of prisoners since the start of the global War on Terror (search), a group of retired Pentagon brass said Wednesday.

"We cannot ignore that there are now dozens of well-documented allegations of torture, abuse and otherwise questionable detention practices," eight former generals and admirals said of prisons in Iraq, Afghanistan and Guantanamo Bay, Cuba.

In-house Pentagon probes didn't require sworn testimony, don't have subpoena power and are examples of the military trying to police itself, the officers, most of whom worked in military law, said in a letter to Bush. In the presidential election campaign, two of them have publicly called for his defeat in November.

Also Wednesday, a Democrat on the Senate Armed Services Committee said months of piecemeal Defense Department investigations have left officials and the public without a full idea of what happened and who is responsible.

"It's about time we had an investigation that is complete and answers all the questions," Sen. Jack Reed of Rhode Island said in a conference call with several reporters.

Photographs disclosed in the spring showed troops threatening prisoners at Iraq's Abu Ghraib (search) facility with dogs, posing them in sexual positions and keeping them naked and hooded.

Though defense officials said the photos portrayed the actions of a few, the controversy has grown to include probes of some 300 allegations of detainee deaths or mistreatment, some during interrogations to gather intelligence.

Critics say fault may ultimately rest with White House or Pentagon leadership for leaving confusion about what was permissible when it declared in early 2002 that terrorist suspects at Guantanamo Bay were not protected under the Geneva Conventions (search).

The retired military leaders who wrote to Bush include Gen. Joseph Hoar, a former commander of U.S. Central Command (search), and Vice Adm. Lee F. Gunn, inspector general of the Navy until his retirement in August 2000.

Hoar is part of a group of retired diplomats and military officers who have said Bush should be voted out of office because his policies damaged U.S. national security interests and America's standing in the world. Gunn is among 12 retired generals and admirals who have endorsed Democratic presidential candidate John Kerry.

The letter was released at a press conference with Human Rights First (search), formerly The Lawyers Committee for Human Rights.

The House and Senate armed services panels are holding hearings Thursday on the two latest probes ordered by the Pentagon into the abuses.

The House Armed Services Committee held a session Wednesday about positive things U.S. forces have done abroad. Committee Chairman Duncan Hunter, R-Calif., said the point of the hearing was "to hear from individuals who have returned from the battlefield about all that they've accomplished."

Five men who commanded units in Iraq spoke of the invasion, the ouster of Saddam Hussein, the fight against the insurgency and postwar efforts to rebuild infrastructure, restart the economy and help create a new Iraqi government.