A court on Wednesday convicted and sentenced two firefighters to a year behind bars in connection with a 2013 nightclub fire that killed more than 200 people in southern Brazil.

The two and six other firefighters had been charged with negligence and falsifying public documents related to the club's fire permit. Prosecutor Joel Dutra successfully argued that the court should drop charges against the other six, saying they had been "induced to error by unclear norms that gave room to different interpretations."

Lawyers for the convicted men said they would appeal.

The fire in January 2013 at the Kiss nightclub in the city of Santa Maria, Rio Grande do Sul state, killed 242 young men and women, all suffocated by toxic smoke that filled a windowless building with no emergency exits.

Soundproofing foam on the ceiling caught fire in the overcrowded nightclub when the lead singer of a country band onstage lit a flare as part of an illegal indoor pyrotechnics show.

Investigators said the burning foam released cyanide, carbon monoxide and carbon dioxide that quickly killed those attending a university party. Dozens of bodies were piled in twisted knots inside the club as hundreds of people stampeded through darkness, trying to reach a single row of four doors that served as both entry and exit. Aside from the dead, 630 people were injured.

The nightclub's two owners and two band members blamed for starting the fire face homicide charges, but are free pending trial. A guilty verdict could bring a prison sentence of up to 30 years, although the complexity of Brazil's legal system and the ability to present numerous appeals means several years can elapse before someone convicted of a crime is put behind bars.