A huge fire engulfed a 200-year-old museum in Rio de Janeiro in Brazil on Sunday, BBC reported. Firefighters attempting to douse the blaze said they were not sure how the fire started.

The National Museum of Brazil, the oldest scientific institution in the country, has more than 20 million items in its collection – including dinosaur bones and a 12,000-year old human skeleton, and artefacts from Egypt and Greco-Roman art. The museum, which once served as the residence for the Portuguese royal family, celebrated its 200th anniversary earlier this year, AP reported.

The fire started at 7.30 pm (4 am on Monday Indian time), after the museum had closed for the day, news website G1 reported. No injuries have been reported yet and firefighting operations are under way.

President Michel Temer said it was “a sad day for all Brazilians”. He added: “Two hundred years of work, research and knowledge have been lost. History cannot be measured by the damage to the building that housed the royal family.”