Brazilian police have arrested four people in connection with a fire at a nightclub that killed 231 people in the southern city of Santa Maria.
Two owners of the Kiss club were arrested on Monday, along with a pair of musicians from the band Gurizada Fandangueira who starred in the ill-fated pyrotechnic show blamed for sparking the tragedy in the university town on Sunday.
Police official Michele Vimmermann said club co-owner Elissandro Spohr and two members of the band have been detained. A second club owner, who has not been named, surrendered to police later in the day, AFP reports.
Brazil's deadliest fire in five decades reportedly started after a band member lit a flare on stage about 2am in a building packed with students.
Police Commissioner Sandro Meinerz said the most plausible cause of the fire were the pyrotechnics used, which released sparks and set the roof alight.
Health Minister Alexandre Padilha said 75 people were in "intensive care ... and are in some danger of dying".
Mr Meinerz said the club had not had valid operating permits since August last year and that its emergency exits led only to the main entrance, which became a deadly bottleneck.
Most of the victims died of smoke inhalation in their desperate bid to escape.
In a statement to police, Mr Spohr acknowledged that the club's licence had expired, adding he had requested a renewal. He also blamed the band for the incident.
The band however denied responsibility and said their accordion player was among the dead.
President Dilma Rousseff pressed mayors across the South American nation to ensure that such a "terrible tragedy never takes place again".
More than 50 of the victims were being buried on Monday. Brazil has declared three days of national mourning.