WASHINGTON -- The seven guards charged with abuses at Abu Ghraib Prison were a rogue band "just having some fun with the prisoners" and not carrying out orders to "soften up" detainees for interrogation, according to Army investigators.

The investigators, whose testimony is contained in court-martial records obtained yesterday by the Los Angeles Times, testified at a secret hearing in Baghdad, Iraq, that they found "absolutely no evidence" that the abuses had been authorized by officers in the Army chain of command.

At the same time, the documents show, a member of the military intelligence battalion operating at the prison testified that interrogators sometimes went too far in trying to extract information from detainees. It is the first known instance of a member of an intelligence unit testifying about misconduct by interrogators.

The intelligence specialist, Sgt. Samuel Jefferson Provance III, said, for example, that a military interrogator he identified as Spc. Armin John Cruz often played rough with detainees when they were taken to special booths to be interviewed.

"Spc. Cruz was known to bang on the table, yell, scream, and maybe assaulted detainees during interrogations in the booth," Provance testified.

"This was not to be discussed. It was kept 'hush hush' by the individual interrogators." It was unclear whether Cruz has been disciplined.

The new information came as officials in Baghdad announced that two more of the seven Abu Ghraib guards will stand trial at courts-martial. One of them, Staff Sgt. Ivan L. "Chip" Frederick II, was accused of taking some of the photographs of mistreatment that have drawn outrage worldwide. He also was charged with directing prisoners to commit sexual acts, which were also photographed, documents outlining the charges said.

And Sgt. Javal S. Davis was charged with taking part in an incident in which a group of detainees was forced into a pile on the prison floor and then physically assaulted by guards.

Frederick and Davis became the second and third military policemen to face courts-martial in connection with the abuse scandal at Abu Ghraib. Both face a more serious level of proceeding than the first soldier charged, Spc. Jeremy Sivits.

While Sivits could be sentenced to a maximum of one year in jail if convicted, the other two may face much heavier sentences in so-called general court-martial proceedings.

Sivits' court-martial is scheduled to begin Wednesday in Baghdad. No date was given for the proceedings against Frederick and Davis.

Military officials emphasized that the investigation of the Abu Ghraib incidents is continuing, along with investigations of what may be dozens of other instances of prisoner abuse there and elsewhere in Iraq. Additional charges are likely to be filed, officials indicated

And while officers in the chain of command may not have known about the abuses, military investigators have said it was their responsibility to know what was going on.