"Scum," screamed animal rights activists to the four suspects during proceedings in the courtroom. Police were forced to intervene and escort the activists from the trial.
The four men, aged 18 to 22, are suspected of torturing two rabbits to death in woodland and in a cellar in southern Stockholm a year ago. One of the rabbits was burned alive. The other animal was kicked to death while a dog was taunted into attacking it.
The incident was caught on a film seized by police during a house search in January, and shown in the courtroom on Thursday.
The film, broadcast by Sveriges Television (SVT) on Tuesday, shows how the laughing men tape the hind legs of the rabbit together, pour inflammable liquid all over the defenceless animal and then set it alight. They then continue to pour flammable liquid on the burning creature until it burns to death.
Police have described the case as one of the most loathsome animal cruelty cases that they have ever had cause to investigate.
Posters on several Swedish community websites have called for the identities of the men to be made known and threats have been made against them in chat rooms, with feelings running high after the film was broadcast by SVT and TV4.
Three of the accused admitted on Thursday to having been at the locations when the alleged offences were committed. The purpose of the cruel episode is reported to have been to train the dog.
"I get severe anxiety when I think about it. I can't understand that I was such an idiot," one of the men said during the trial, according to the Aftonlbadet tabloid.
The fourth man denies all charges against him.