The Rio de Janeiro governor, Wilson Witzel, has declared three days of mourning for the deaths of those affected by the floods and the fire.
Three teenagers are still in hospital after the blaze, including one who is in a serious condition.
Belotti did not take questions but said a reported lack of permits for the building was not a factor in the accident.
"We can't tell you the cause of the fire; that needs to be investigated".
"The kids from the Flamengo youth team were sleeping there at the time", a firefighter told Brazilian news network GloboNews. "Thank God I managed to run and I'm still alive".
Flamengo, based in Rio de Janeiro, is considered as one of the most supported and established soccer clubs in the history of Brazilian soccer, and has featured former Brazilian legends Zico, Romario, Bebeto and Ronaldinho.
"We are distraught", Flamengo president Rodolfo Landim told reporters, according to The Associated Press.
In a statement shared by the presidency, he added that he was dismayed by "this tragedy. which has taken the lives of young people who had started the journey towards realizing their professional dreams".
Flamengo are one of Brazil's most successful clubs, with five league titles and a Copa Libertadores - the South American equivalent of the Champions League - to their name.
"All of the young people in my generation see ourselves reflected in this tragedy", he added, noting that some young players weren't well-nourished at the club either.
The club posted a graphic on Twitter that said "Flamengo is in mourning".
What do we know so far?
Family, friends and fans gathered to pay their respects at a mass ceremony held in memory of the young players and staff lost in the Flamengo football club fire.
"Most didn't make it because there was so much fire", Barbosa said.
Local media reports suggest the fire happened in an older part of the centre that was scheduled to be torn down.
"The lodging area hit by the fire is not included in the last project approved by our licensing", it said.