OVIEDO, Spain

At least one person has been killed following a huge explosion Tuesday evening at a petrochemical plant in the industrial Catalan city of Tarragona.

The blast was so strong that it caused a building around three kilometers (about two miles) away to collapse. It was there that the death occurred.

Around three hours after the explosion, 29 firefighter crews remain on the scene. They are working to control the powerful blaze before it reaches other chemical deposits.

Firefighters are also searching the grounds for people who may be trapped in the plant.

So far, the local government has said two people have been severely injured, with one in critical condition, and six others received lighter injuries.

The plant belongs to the company IQOXE, which produces highly explosive chemicals like ethylene oxide.

Residents of the area were originally told to stay indoors after the explosion, but authorities have since said it presents no further danger to those who live nearby.

“We can confirm that the air is not toxic. We told people to stay confined to their houses for preventative reasons,” Catalan Interior Minister Miquel Buch said on local radio station RAC1.