According to the museum’s website, it has more than 20,000 items related to the history of Brazil and other countries, and that many of its collections came from members of Brazil’s royal family.
Connected to the Federal University of Rio de Janeiro, the museum has expositions that include anthropology, archeology and paleontology, among others.
The vice director of the museum, Luiz Fernando Dias Duarte, told Globo news the museum suffered chronic underfunding.
“Everybody wants to be supportive now. We never had adequate support,” he said.
Brazil has struggled to emerge from its worst recession in decades. The state of Rio de Janeiro has been particularly hard hit in recent years thanks to a combination of falling oil prices, mismanagement and massive corruption.
Sgt. Moises Torres from the state’s firefighting headquarters said firefighters were working to put out the blaze.