Updated

Officials at a federal prison in New York hindered an investigation that determined that as many as 20 guards abused detainees (search) who were picked up shortly after the Sept. 11 (search) attacks, the Justice Department (search) reported Thursday.

Investigators found hundreds of videotapes that officials at the Metropolitan Detention Center in Brooklyn had said were destroyed or erased, according to a report by the department's internal watchdog, Inspector General Glenn A. Fine.

The tapes confirmed the detainees' allegations of abuses that were outlined in a June report by Fine, the follow-up inquiry said.

Investigators said many of the 84 detainees were mistreated. Guards slammed them against walls, twisted their arms, conducted unnecessary strip searches, banged on cell doors while detainees were trying to sleep, and hung an American flag T-shirt on the wall that said, "These colors don't run."

Also, conversations between the detainees and their lawyers were taped, the report said.

"We believe many staff members acted unprofessionally and abusively," the report said, noting that the tape showed some guards who denied any abuse actually participated in the mistreatment.

Fine also criticized prison officials for "inconsistent and inadequate" responses to investigators' requests for the tapes.

The report recommended that 10 of the guards be disciplined by the Bureau of Prisons and two more attend counseling. Four guards no longer work at the prison, but the report said their new employers should be told of the Justice Department findings. The inspector general could not identify the others involved.

Department spokesman Mark Corallo said the agency's civil rights division and the U.S. attorney for the Eastern District of New York will review the report and the videotapes to see if anyone should be prosecuted.

"We agree with the inspector general that even the intense emotional atmosphere surrounding the attacks, particularly in New York City where smoke was still rising from the rubble of Ground Zero, is no excuse for abhorrent behavior by Bureau of Prisons personnel," Corallo said.

Two Democratic members of the House Judiciary Committee, Reps. John Conyers of Michigan and Jerrold Nadler of New York, asked Attorney General John Ashcroft to punish the guards and to take steps to prevent a repeat of the abuse.

"Actions such as these not only constitute a disservice to the department but seriously undermine our war against terror," they said in a letter.

In June, the inspector general found "significant problems" with the treatment of 762 foreigners rounded up nationwide for immigration violations after the terrorist attacks. Only one, Zacarias Moussaoui, was charged with any terrorism-related crime.

The report found that the allegations of abuse were limited to the Brooklyn facility.

"Most detainees did not have complaints about their treatment at other institutions or by other officers," the report said.