An explosion at a factory in Spain’s autonomous Catalonia region has caused a huge fire, local officials say.

The blast at the factory south of the port city of Tarragona was probably the result of a chemical accident, Catalonia’s civil defence agency said.

It urged residents of Tarragona and a number of nearby towns to close windows and doors and stay indoors.

It is not clear if there have been any injuries after Tuesday’s incident in La Canonja municipality.

The explosion happened at 18:40 local time (17:40 GMT), Efe news agency reports.

Dozens of firefighters have been dispatched to the area to tackle the blaze.