NANTES, France (AP) " A fire broke out Saturday in the Gothic cathedral of the western French city of Nantes, shattering stained glass windows and sending black smoke spewing from between its towers as firefighters fight the blaze.

Residents and tourists watched aghast, and emergency workers cordoned off the area around the St. Peter and St. Paul Cathedral, in the historical center of this city on the Loire River. The local firefighter service warned people to avoid the area while efforts to extinguish the blaze are under way.

A City Hall official says the fire broke out Saturday morning inside the cathedral, and the cause is unclear. The official is not authorized to be publicly named.

The fire broke the main stained glass windows between the two towers of the 15th century cathedral, which also suffered a serious fire in 1972.

The fire is bringing back memories of the devastating blaze in Notre Dame Cathedral in Paris last year that destroyed its roof and collapsed its spire and threatened to topple the medieval monument.