A fire has broken out in the spire of the medieval cathedral in the French city of Rouen, authorities said.

Mayor Nicolas Mayer-Rossignol posted on X, formerly Twitter: “The beginning of a fire is underway on the spire of the cathedral of Rouen. The origin is unknown at this stage. All public resources are mobilised.”

Smoke billows from Cathedral spire
Officials say the fire, which was discovered by construction workers, was under control within 90 minutes (Vivien Leservoisier via AP)

Stephane Gouezec, of the Seine-Maritime firefighters, later said the source of the fire had been located — in a spire that was under renovation — and crews were working to ensure there were no remaining “hot spots”.

But he told reporters the risk of the flames spreading was low because the fire was in an area where there was mostly metal.

Mr Gouezec said construction workers were the first to notice the fire and alerted authorities.

The regional administration in Normandy posted online that the cathedral had been evacuated and a security perimeter was in place.

The cathedral had been evacuated and a security perimeter was in place, according to regional officials.

Exterior of the French cathedral in Rouen
The medieval cathedral in Rouen is widely known from a series of paintings by Claude Monet (AP Photo/Michel Euler, File)

Witnesses speaking on BFM television described smoke emanating from the spire and recalled a devastating fire in 2019 at Notre Dame Cathedral in Paris that toppled its spire and collapsed its roof.

The cathedral in Paris, a major landmark, is scheduled to reopen in December after an unprecedented reconstruction effort. The cause of that fire was deemed an accident.