(CNN)Ten young football players were killed and three others were hurt when a fire broke out at a training center of Brazilian football club Flamengo, authorities said.
Flamengo is one of Brazil’s biggest and most popular clubs, playing their home matches in Rio de Janeiro.
Rio Gov. Wilson Witzel announced three days of mourning to remember the victims, state-run news agency Agencia Brasil reported.
The derby between Flamengo and bitter Rio rivals Fluminense — one of the biggest matches on the Brazilian calendar — was scheduled for Saturday at the Maracana stadium, but has now been postponed.
In a news conference, authorities identified the victims as: Christian Esmério Candido,15; Athila de Souza Paixão,14; Arthur Vinícius de Barros Silva Freitas, 14; Bernardo Pisetta, 14; Pablo Henrique da Silva Matos, 14; Vitor Isaías, 15; Gedson Santos, 14; Jorge Eduardo Santos, 15; Rykelmo de Souza Vianna, 16; and Samuel Thomas Rosa, 15.
The wounded were identified by authorities as Jonathan Cruz Ventura, 15; Cauan Emanuel Gomes Nunes, 14, and 15-year-old Francisco Diogo Bento Alves.
Earlier reports misidentified some of the dead football players.
Beatriz Busch, the public health secretary for the state of Rio de Janeiro, said the players wounded in the fire were recovering in the hospital.
One of the wounded, Busch said, was in serious condition Friday with burns over about 35% of his body, including his arm and neck.
Speaking to reporters late Friday morning, Flamengo President Rodolfo Landim offered his condolences to “everyone” and said the incident was “certainly the biggest tragedy this club has been through in the past 123 years.”
“It’s a huge sadness, it’s not easy,” Landim said.
Gen. Hamilton Mourao, Brazil’s vice president and one of the club’s most high-profile fans, wrote: “As a fan and sportsman I stand in solidarity with the families, the club and the Red-and-Black nation. May God comfort all.”
Real Madrid forward Vinicius Junior, who joined that club from Flamengo last year, said: “Just remembering the nights and days I spent at the training center, it gives me goosebumps.
“I still can’t believe it but praying for all. God bless everyone’s family.”
Flamengo posted that the club “is in mourning.”
Pele, Brazil’s three-time World Cup winner, tweeted: “My day began with the news about the fire at Flamengo’s training ground — a place where young people pursue their dreams.
“It’s a very sad day for Brazilian football.”
Correction: This story has been updated to correct the names of the dead and injured.