At least 233 people have been killed in a fire at a nightclub in southern Brazil after a band's pyrotechnics show set the building ablaze, local police said.

Bodies are still being removed from the Kiss nightclub in the southern city of Santa Maria, said Major Gerson da Rosa Ferreira, who is leading rescue efforts at the scene for the military police.

He said the victims died of asphyxiation or from being trampled. There were as many as 500 people inside the club when the fire broke out.

Luiza Sousa, a civil police official in Santa Maria, said the blaze started when a member of the band or its production team ignited a flare, which then set fire to the ceiling.

The fire spread "in seconds", Ms Sousa said.

Rio Grande do Sul state Health Secretary Ciro Simoni said emergency teams from all over the state have been sent to the scene.

Santa Maria is 300km west of the state capital of Porto Alegre.

Rio Grande do Sul Governor Tarso Genro said it was "a sad Sunday" and that "all possible measures" are being taken in response.