Edgar Matisorevic said the prisoners ran naked in the prison's yard but could not remember who had ordered it, and that they had to sing Croatian patriotic songs, which he had taught them and ordered them to sing.
The witness said he beat a prisoner having found out that he had walked down a street with a child impaled on a bayonet.
He recalled that the first on the indictment in the Kerestinec case, Stjepan Klaric, a commander at the time relevant to the indictment, was present at the interrogations, as was his deputy Drazen Pavlovic, who is also indicted.
The witness said the third indictee, Viktor Ivancin, would sometimes be present at the interrogations.
Marijan Biskic, deputy military police chief when the military police took over the command in the Kerestinec prison, said he knew about the torture in the prison when Klaric was commander only from the media.
He said that if crimes had been committed at the prison, the Security and Information Service would have had the duty to inform the military police, which would have investigated them.
Biskic said the only complains regarding the prison were about hygiene, cleanliness and house rules.
Apart from Klaric, Ivancin and Pavlovic, two other men are accused in the case, Zeljko Zivec and Goran Strukelj.
The trial resumes on September 20.