At least 233 people have died in a fire that swept through a nightclub in a university city in southern Brazil, police and officials say.
Local media say the fire began when a band let off fireworks at the Kiss club in Santa Maria, Rio Grande do Sul.
Many victims reportedly inhaled toxic fumes or were crushed as panicking clubbers tried to escape.
Bereaved families have been weeping over the coffins of their loved ones at a gym used as a temporary mortuary.
Out of respect for the dead, Brazil postponed a ceremony due on Monday in the capital, Brasilia, to mark 500 days to the 2014 football World Cup.
The first funerals in Santa Maria are expected on Monday morning, local newspaper Diario de Santa Maria reports.
Authorities have released the names of 230 of the victims, with three bodies still to be identified.
According to Brazilian broadcaster Globo, most of the victims were aged between 16 and 20.
More than 100 people were being treated in hospital, mostly for smoke inhalation.
President Dilma Rousseff, who cut short a visit to Chile, has been visiting survivors at the city's Caridade hospital along with government ministers.
She said earlier that everything possible would be done to help the injured and the families of the victims.
"I would also like to say to the Brazilian people and to the people of Santa Maria that we stand together at this time, and that even though there's a lot of sadness, we will pull through," she said, speaking from Chile.
A firefighter told BBC News he had never seen such a tragedy in his life, with the victims "so young".
The priority for the authorities is now to identify the dead with many distressed relatives arriving at the scene, but in the hours ahead the focus will turn to the cause of this accident and safety procedures at the club, the BBC's Gary Duffy reports from Sao Paulo.
The death toll, which had earlier been put at 245, was revised down by fire officials.
'Ceiling on fire'
The fire broke out some time after 02:00 (04:00 GMT) when between 300 and 500 people are believed to have been in the club, where a band was playing.
According to Diario de Santa Maria, students from the city's federal university (UFSM) were holding a freshers' ball.
Thick smoke engulfed the venue after acoustic insulation caught fire, officials say.
"We looked up at the ceiling in front of the stage and it was catching fire," eyewitness Luana Santos Silva, 23, told Brazil's Globo TV.
"My sister grabbed me and dragged me out on the ground."
The exit, she said, was a "small door for lots of people to come out by".
The young woman's sister, Aline Santos Silva, 29, commended the emergency services: "Help arrived really quickly, ambulances, police."
Fire crews tried knocking through an exterior wall to help those trapped inside to escape.
Fifty bodies were found in the club's toilets, a doctor told AP news agency.
"The toxic smoke made people lose their sense of direction so they were unable to find their way to the exit," said Dr Paulo Afonso Beltrame, speaking by phone from Caridade hospital.
"Apparently they confused the bathroom door with the exit door."
Speaking to BBC Brasil, Sergeant Arthur Rigue, from the local fire department, said: "I never witnessed a tragedy like this in my whole career.
"These people are so young… There were many bodies piled up in various parts of the place. Some were in the toilet. They died of asphyxiation."
Fire chief Guido de Melo told local media. "People started panicking and ended up treading on each other."
A temporary morgue was set up in a local gym as the city's main morgue is unable to cope.
Family members came to identify the dead, led in one by one to see the bodies, Diario de Santa Maria reports.
President Rousseff said the air force had made "resources" available at an air base near Santa Maria to help.
Santa Maria has a population of about 250,000 people, while UFSM has some 27,000 students.