A huge blaze is under way at the famed Notre Dame cathedral in the French capital, Paris, according to the city’s fire service.
Footage showed flames coming out of the Gothic cathedral on Monday, with smoke billowing from the roof.
The spire of the building was later seen collapsing.
“A terrible fire is under way at Notre Dame Cathedral in Paris,” Mayor Anne Hidalgo said on Twitter.
It was not immediately clear what had caused the fire. France 2 television reported that police were treating the incident as an accident.
According to AFP news agency, the fire was noticed at about 6:50pm local time (14:50 GMT).
The police urged people to avoid the area and facilitate the passage of emergency vehicles.
French President Emmanuel Macron cancelled his national address due to the fire. A presidential official said Macron was to go to the scene of the blaze.
Notre Dame is distinguished for its size, antiquity and architectural interest.
The cathedral, which dates back to the 12th century and is famous for featuring in Victor Hugo’s classic novel the Hunchback of Notre Dame, attracts millions of tourists every year.
It was here that Christian crusaders prayed before going to fight in the Holy Land, where revolutionaries defiled representations of French kings and Napoleon crowned himself emperor in 1804.
It was in the middle of $6.8m renovations, with some sections under scaffolding, while bronze statues were removed last week for works.