An arson inquiry has been launched after a fire broke out in the Gothic cathedral of the western French city of Nantes, shattering stained glass windows and sending black smoke spewing from between its towers.
Residents and tourists watched aghast, and emergency workers cordoned off the area around the St Peter and St Paul Cathedral, in the old centre of the city on the Loire River.
A City Hall official said the fire broke out Saturday morning inside the cathedral, and the cause is unclear.
Firefighters said the roof is not affected by the fire and was "under control".
They brushed aside comparisons with Notre Dame cathedral in Paris whose lead roof and spire burned down in April 2019.
The Nantes fire for many will bring back memories of that devastating blaze that threatened to topple the medieval monument.
"After Notre-Dame, the Saint-Pierre-et-Saint-Paul cathedral, in the heart of Nantes, is in flames. Support for our firefighters who take all risks to save this Gothic jewel of the city," French President Emmanuel Macron wrote on Twitter.
Saturday's fire broke the main stained glass windows between the two towers of the 15th century cathedral, which also suffered a serious fire in 1972.
"It is a part of our history, a part of our heritage" Nantes mayor Johanna Rolland told reporters.
"We all have these images in mind, this story in our hearts, but at this stage the situation does not seem to be comparable to that of 1972."
French prime minister Jean Castex and French interior minister Gerald Darmanin will be among officials travelling to Nantes on Saturday in reaction to the blaze.