The fire started after the launch of fireworks during a performance of the musical group on stage, reports Korrespondent.
Sparks hit the ceiling where there was soundproof foam, and from there the flames began to spread. At the time of the tragedy there were about two thousand people inside.
Rescuers have not yet completed the work on the scene. According to Police Major Gerson da Rosa Ferreira, some of the victims suffocated, and some were killed in the stampede. The ensuing fire caused panic among the visitors and many people could not get to the emergency exit.
The guards of the Brazilian nightclub were blocking the only way out in the first minutes of the fire.
According to head of the Rio Grande do Sul fire department Colonel Guido de Melo, citing witnesses this blocking created panic and led to stampede.
"According to the people who were inside, security guards blocked the exit which did not allow for rapid evacuation. This caused even more panic and stampede," said the head of the fire service.
According to one version, the guards in the first minutes after the fire were not aware of the outbreak, and were trying not to let the visitors leave the establishment without paying.
According to de Melo, the club was equipped with only one exit, and fire and rescue workers had to punch holes in the walls to get into the club. In addition, the permit's term of the club expired last year.
It also reported that Brazilian President Dilma Rousseff cut short her visit to Chile due to the fire, where she took part in the summit of the European Union and the Community of Latin America and the Caribbean, reports Agence France-Presse.
Representatives of the authorities believe that the fire happened due to gross violation of fire safety rules. During the party, pyrotechnics was used on stage. It ignited the insulation and the room became shrouded in acrid smoke.
The police fear that the number of victims of a fire in Brazil could rise by several fold because investigators have just started to count the dead. Around 200 people are in hospital, the state of 8 being critical.