SANTA MARIA, Brazil (Reuters) - Brazilian police investigating a nightclub fire that killed 231 people detained on Monday the owners of the club and two band members whose pyrotechnics show authorities say triggered the blaze as the focus turned to finding those responsible for the tragedy.
No charges were filed against the four men, but prosecutors said they could be held for up to five days as police press them for clues as to how the fire early Sunday morning could have caused so many deaths.
Stunned residents in the southern city of Santa Maria attended a marathon of funerals beginning in the pre-dawn hours. As sunset approached, friends and family members readied for a candle-lit procession through the streets of the city.
The tragedy came as Brazil prepares to host the 2014 World Cup soccer tournament and 2016 Olympics, putting its safety standards and emergency response capabilities in the international spotlight.
President Dilma Rousseff, who cut short a visit to Chile to fly to the scene of the disaster on Sunday, called for a minute of silence before addressing a meeting of newly elected mayors in the capital, Brasilia.
"The pain I saw in Santa Maria was indescribable," Rousseff said. "Faced with this tragedy, it is our duty to make sure it never happens again."
Most of the dead were suffocated by toxic fumes that rapidly filled the Kiss nightclub after the band set off a flare at about 2:30 a.m. on Sunday, authorities said.
The club's operating license was under review for renewal after expiring last year.
Witnesses said bouncers initially blocked the only functioning exit because they believed fleeing customers were trying to skip out on their bar tabs.
Tarso Genro, governor of the prosperous southern state of Rio Grande do Sul where the disaster occurred, said authorities had shifted their focus from rescue and taking care of the wounded to investigating the scene.
"We're going to find out who was responsible," he vowed.
The death toll was revised down to 231 from 233 as officials said some names had been counted twice. Eighty-two people were hospitalized, 75 of them in serious condition, officials said.
Mourning throughout Brazil was mixed with frustration at a culture of lax regulation blamed for putting lives at risk.
"So many young ones with all of their lives ahead of them," Brazilian soccer legend Pele wrote on Twitter. "The government has to make a priority of event security in this country!"
Relatives and friends of the dead demanded accountability, signaling the start of a wave of police probes, lawsuits and recriminations that could drag on for months or even years.
Based on testimony from more than 20 witnesses, investigators are now certain that the band's pyrotechnics show triggered the blaze, police official Sandro Meinerz said.
The band's guitarist, Rodrigo Lemos Martins, 32, said he doubted the band was responsible for the blaze. "There were lots of wires (in the ceiling), maybe it was a short circuit," he was quoted as saying in Folha de S.Paulo newspaper.
The band's accordion player, Danilo Jaques, 30, was among those killed, but the other five members survived. The band's vocalist and production engineer were detained by police investigating who was responsible for firing the flare, according to Brazilian media.
It seems certain others will share the blame for Brazil's second-deadliest fire ever. The use of a flare inside the club was a clear breach of safety regulations, fire officials said.
Some details may never be known. Meinerz said the club owner told authorities that the club's internal video surveillance system had stopped working three months ago.
Clubs and restaurants in Brazil are generally subject to a web of overlapping safety regulations, but enforcement is uneven and owners sometimes pay bribes to continue operating.
The investigation of the Kiss fire could drag on for years. After a similar fire at an Argentine nightclub in 2004 killed 194 people, more than six years passed before a court found members of a band criminally responsible for starting the blaze and causing the deaths.
That tragedy also provoked a massive backlash against politicians and led to the removal of the mayor of Buenos Aires.
Civil lawsuits stemming from the Brazil fire are likely to be directed at the government because the owners of the nightclub probably don't have much money, said Claudio Castello de Campos, a Brazilian lawyer who has handled big cases including the crash of a TAM Airlines jet in Sao Paulo in 2007.
Castello de Campos disputed some statements by local officials that the Kiss nightclub could have continued operating legally while it was waiting for its license to be renewed. "If the license was expired, that's an irregular situation," he said.
Valdeci Oliveira, a legislator in Rio Grande do Sul state, said he and his colleagues would seek to ban pyrotechnics displays in closed spaces such as nightclubs.
"It won't bring anybody back but we're going to introduce the bill," Oliveira said on his Twitter feed.
The Brazil fire is the worst to hit an entertainment venue since a fire on Christmas Day in 2000 engulfed a mall in Luoyang, China, killing 309 people.
Additional reporting by Eduardo Simões in Sao Paulo; Writing by Brian Winter; Editing by Todd Benson, Kieran Murray and Eric Beech