As many as 20 guards at a Brooklyn, N.Y., federal prison abused detainees arrested after the Sept. 11 attacks, Justice Department (searchinvestigators reported Thursday in a follow-up look at allegations of abuse at the facility.

While the guards did not beat any of the detainees, they did slam some of them against the wall, kept them restrained for long periods, twisted their arms and stepped on their leg chains, according to the report by Inspector General Glenn A. Fine (search).

Fine recommended that 10 of the guards be disciplined by the Bureau of Prisons (searchand another two undergo counseling. Four guards no longer work at the prison, but Fine's report said their new employers should be told of his findings. The inspector general could not identify any others involved.

The inspector general also said that prison officials had denied the existence of videotapes showing abusive behavior.

In June, the inspector general found "significant problems" with the treatment of 762 foreigners on immigration violations after the terrorist attacks. In that report, the inspector general identified a "pattern of physical and verbal abuse" by guards.

The report issued Thursday provided additional details of abuse, looking at allegations made by 30 detainees against some 20 prison guards.

Investigators determined jail personnel improperly taped detainees' meetings with their lawyers, unnecessarily used 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."

The report found that the allegations of abuse of people detained after the terrorist attacks 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.