The spire of the famous cathedral in French Rouen caught fire on Thursday morning, the cause of the fire is unknown, the city's mayor Nicolas Mayer-Rossignol said on social network X.

"The fire started in the spire of the cathedral, its cause is not yet known. All resources have been thrown to extinguish it," the mayor said.

The photo posted by him shows thick clouds of smoke rising from the cathedral.

Visitors were evacuated.