Brazilian police have used pepper spray, tear gas and batons to hold back protesters angry at the loss of the country’s National Museum to fire.

A crowd of protesters tried to push through the museum gates several times on Monday (local time), demanding to see the damage caused by the blaze that gutted the museum on Sunday.

They also called on the government to rebuild the burned-out National Museum, as the country mourned the irreplaceable treasures lost and traded accusations of blame for the fire.

The museum held Latin America’s largest collection of historical artefacts, and the damage was feared to be catastrophic.

One official told a Brazilian news outlet that as much as 90 per cent might have been destroyed. Some parts of the collection were stored at other sites.

For many in Brazil, the state of the 200-year-old natural history museum quickly became a metaphor for what they see as the gutting of Brazilian culture and life during years of corruption, economic collapse and poor governance.

“It’s a crime that the museum was allowed to get to this shape,” said Laura Albuquerque, a 29-year-old dance teacher who was in a crowd protesting outside the gates. “What happened isn’t just regrettable, it’s devastating, and politicians are responsible for it.”

A meteorite display that survived the fire. Photo: AAP

The cause of the fire that broke out Sunday night (local time) was not known. Federal police will investigate, as the museum was part of the Federal University of Rio de Janeiro.

But protesters, commentators and museum directors themselves said years of government neglect had left the museum so underfunded that its staff had turn to crowdfunding sites to open exhibitions.

Museum deputy director Luiz Fernando Dias Duarte criticised authorities for starving the museum of vital funding while spending lavishly on stadiums to host the FIFA World Cup in 2014.

“The money spent on each one of those stadiums – a quarter of that would have been enough to make this museum safe and resplendent,” he told Brazilian television in front of the still-smoldering ruins.

Roberto Leher, rector of the Federal University of Rio de Janeiro, said it was well known that the building was vulnerable to fire and needed extensive repairs. Mr Duarte said he was in the habit of unplugging everything in his office at night because of the risk.

Civil defence authorities were concerned that internal walls and the roof could collapse further, so officials have not yet been able to fully account for the losses.

Mr Duarte said anything held in the main building was likely destroyed. Cristiana Serejo, a museum vice-director, told the G1 news portal that as little as 10 per cent of the collection might have survived.

The building was once home to the royal family, and the museum’s collection included pieces that belonged to them.

Even after Sunday’s fire, signs of disrepair were evident: The fencing was dilapidated, stonework was cracked and lawns appeared untended.

In a sign of how strapped the museum was, when a termite infestation last year forced the closure of room that house a 13-yard-long dinosaur skeleton, officials turned to crowdfunding to raise the money to reopen the room.

However, there was recent approval for a renovation, including an upgrade of the fire-prevention system, officials said.

President Michel Temer announced on Monday that private and public banks, as well as mining giant Vale and state-run oil company Petrobras, have agreed to help rebuild the museum and rebuild its collections.

French President Emmanuel Macron offered in a tweet to send experts to help rebuild the museum.

-AAP