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.
The cathedral was in the middle of $6.8m renovations, with some sections under scaffolding, while bronze statues were removed last week for works.
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 de Paris in flames. Emotion of a whole nation. Thought for all Catholics and for all French. Like all our compatriots, I am sad tonight to see this part of us burn,” Macron said on Twitter.
Al Jazeera’s Natacha Butler, reporting from Paris, said she saw tears streaming down the face of some onwatchers.
“The cathedral is a French icon, it is a symbol of Paris all over the world,” she said. “To see it in flames is extremely sad for so many people