Police in Brazil say the nightclub fire that killed 235 people was caused by cheap fireworks meant for outdoor use.
As people in Santa Maria again marched demanding justice for the victims, the chief investigator has backed witness accounts suggesting the band on stage had let off flares.
“The people who bought this material knew it was for external use and not to be used indoors but they used it because it was cheaper,” said police inspector Marcelo Arigony.
He said that whereas indoor fireworks cost 70 reales (25 euros), the band chose cheaper ones from a local shop that only cost 12.5 reales (under 5 euros).
The inspector, who lost a cousin in the disaster, said the fireworks were part of the band’s show and they had even worn gloves on stage.
A band member is among several people who have been arrested.
Video filmed on Tuesday shows the damage to the Kiss nightclub from Sunday’s fire. Soot covers the doors and debris is strewn across the floor.
The authorities also say the venue had too many people, combustible material in the ceiling, and faulty fire safety equipment.
The country’s health minister said the lives of dozens being treated in hospital were in danger.
Several other towns in Brazil have announced stricter controls on clubs.