About 40,000 residents in the towns of Igualada and Odena were ordered to stay indoors and keep their windows shut after an explosion at a nearby chemical company sent a massive orange cloud of potentially toxic fumes into the sky.

As the Associated Press reported:

A spokeswoman for Catalonia's regional firefighting department said the blast occurred Thursday when products being delivered to a warehouse in the city of Igualada became mixed, exploded and set a truck on fire. She said two people were slightly injured.



The Red Cross cited firefighters as saying the chemicals were nitric acid and ferric chloride.

The cloud has begun to dissipate.

The explosion happened at Simar, a chemical distribution plant, RT reported.