A fast-moving fire roared through a crowded nightclub in southern Brazil early Sunday, within seconds filling the space with flames and a thick, toxic smoke that killed more than 230 panicked partygoers who gasped for breath and fought in a stampede to escape.

It appeared to be the world's deadliest nightclub fire in more than a decade.

Firefighters responding to the blaze at first had trouble getting inside the Kiss nightclub because bodies partially blocked the club's entryway.

Witnesses said a flare or firework lit by band members started the blaze in Santa Maria, a university city of about 260,000 people. Officials at a news conference said the cause was still under investigation – though police inspector Sandro Meinerz told the Agencia Estado news agency the band was to blame for a pyrotechnics show and that manslaughter charges could be filed.

Television images showed black smoke billowing out of the Kiss nightclub as shirtless young men who had attended a university party joined firefighters using axes and sledgehammers to pound at windows and hot-pink exterior walls to free those trapped inside.

Bodies of the dead and injured were strewn in the street and panicked screams filled the air as medics tried to help. There was little to be done; officials said most of those who died were suffocated by smoke within minutes.

Within hours a community gym was a horror scene, with body after body lined up on the floor, partially covered with black plastic as family members identified kin.

Outside the gym police held up personal objects – a black purse, a blue high-heeled shoe – as people seeking information on loved ones looked crowded around, hoping not to recognize anything being shown them.

Guido Pedroso Melo, commander of the city's fire department, told the O Globo newspaper that firefighters had a hard time getting inside the club because "there was a barrier of bodies blocking the entrance."

Teenagers sprinted from the scene after the fire began, desperately seeking help. Others carried injured and burned friends away in their arms. Many of the victims were under 20 years old, including some minors.

"There was so much smoke and fire, it was complete panic, and it took a long time for people to get out, there were so many dead," survivor Luana Santos Silva told the Globo TV network.

The fire spread so fast inside the packed club that firefighters and ambulances could do little to stop it, Silva said.