Notre-Dame cathedral in central Paris, one of the world’s best known and most visited monuments, was devastated by fire on Monday evening in a cultural catastrophe with few precedents in peacetime.

The fire appears to have started on the roof at the back of the cathedral, where restoration work was under way with extensive scaffolding. It spread rapidly to send flames and smoke high into the sky above the French capital.

Firefighters, police and reporters in the square in front of the famous twin towers of the medieval cathedral saw flames spreading across the roof and were bombarded with a hail of cinders and red-hot fragments of wood.

The 750-tonne spire over the altar at the centre of the cathedral and much of the roof collapsed after it was engulfed in flames. The area around the cathedral, on the Ile de la Cité in the heart of Paris, was evacuated.

As nearly 500 firefighters struggled through the night to bring the flames under control, French authorities said they thought they had saved the stone structure of the building, even though the collapse of the blazing roof is certain to have damaged priceless works of art in the main body of the cathedral.

Emmanuel Macron, France’s president, immediately cancelled a television speech to the nation in which he was set to outline his plans for the political future of France after mass protests by the anti-government gilets jaunes movement and a two-month “great national debate”.

He appeared in front of the still-burning monument shortly before midnight on Monday to announce the launch of a fund to rebuild Notre-Dame.

“We were able to build this cathedral more than 800 years ago and over the centuries to enlarge it and improve it, and I tell you very solemnly this evening, this cathedral — we will rebuild it, all together,” he said.

“Notre-Dame de Paris is our history, our literature, the life of our imagination, the place where we have lived all our great moments, our epidemics, our wars, our liberations. It’s the epicentre of our life,” he said, “It’s a cathedral of all the French even when they have never been to it. This history is ours, and it is burning.”

The fire spread quickly from the roof area above the central crossing © Geoffroy Van der Hasselt/AFP

Parisians and tourists clustered on bridges and on the banks of the Seine to witness the disaster.

“The interior must be a catastrophe now,” said Adrián Almoguera, a history of architecture student from Spain who lives in Paris. “I’m afraid for the stained-glass windows. They are very important and the fire was over the windows. I imagine they just exploded . . . The choirs and the artworks must be destroyed.”

The rose window in the south transept is one of the treasures of the cathedral

Some passers-by were in tears at the sight of the blazing cathedral. “I feel as though I’ve been murdered,” said one Paris resident returning to her flat after seeing the fire.

More than an hour after the fire erupted, firefighters on at least one side of the building seemed unable even to reach the blaze. On the south side a lone firefighter sprayed water from a vehicle-mounted ladder towards the roof, but the water did not come close to reaching the blaze.

By midnight, however, the flames had begun to diminish under a deluge from fire hoses on all sides of the roof.

The Unesco world heritage site attracts more than 12m visitors every year, and houses priceless works of art. Parts of the roof and building of the cathedral, built between the 12th and 14th centuries, were clad in scaffolding for renovation. Statues had recently been removed by crane for repair.

“A monument like Notre-Dame requires permanent restoration,” Jack Lang, former French culture minister, said on BFMTV.

Anne Hidalgo, Paris mayor, called it a “terrible fire” and asked people to stay clear of a security cordon outside the building.

Donald Tusk, president of the European Council, tweeted: “Notre-Dame of Paris is Notre-Dame of all Europe. We are all with Paris today.”

Jim Jennings and his wife Lynn Hiestand were in their flat 100 metres from Notre-Dame when they saw smoke emerging.

Large crowds watched the church burn © Rebecca Rose/FT

“Our apartment looks straight up at the flying buttresses at the back half of the cathedral,” said Mr Jennings, a retired consultant. “It was an extremely fast-moving conflagration. It was completely enveloped, very quickly.”

Police entered their building and knocked on the doors to evacuate the flats. The couple, both American, were among a crowd of people standing on the right bank of the Seine after the Ile de la Cité was evacuated. Behind the buildings, water being sprayed on Notre-Dame was just visible. “It’s just tragic,” Ms Hiestand said. “I think it’s gone.”

One onlooker said the fire was “too, too sad . . . a truly medieval blaze for a medieval building”.