A fire has broken out at the famous Notre-Dame cathedral in Paris.
The cause of the blaze was not immediately clear, but officials say that it could be linked to renovation work.
Images on social media show plumes of smoke billowing into the air above the 850-year-old Gothic building.
Last year, the Catholic Church in France launched an urgent appeal for funds to save the cathedral, which was starting to crumble.
A major operation is under way to tackle the blaze, which broke out on Monday afternoon.
An area surrounding the building in central Paris has been cleared, officials said.
The mayor of Paris, Anne Hidalgo, described it as a “terrible fire” and urged people at the scene to respect the boundaries set up by fire crews in order to ensure that they remain safe.
— Bob le Centriste (@BobLeCentriste) April 15, 2019
Un terrible incendie est en cours à la cathédrale Notre-Dame de Paris. Les @PompiersParis sont en train de tenter de maîtriser les flammes. Nous sommes mobilisés sur place en lien étroit avec le @dioceseParis. J’invite chacune et chacun à respecter le périmètre de sécurité. pic.twitter.com/9X0tGtlgba
— Anne Hidalgo (@Anne_Hidalgo) April 15, 2019