A tower in Madrid’s business district was evacuated Tuesday after an explosion in a technical room caused a fire and heavy smoke on the 25th floor of the Moeve building, formerly known as the Cepsa Tower.

Axar.az reports, citing El Pais, emergency services evacuated hundreds of workers from the 49-story skyscraper, while three people who had taken shelter in safe areas inside the building were later evacuated unharmed.

Two workers were treated for mild smoke inhalation and released at the scene, while a passerby received medical attention after suffering an anxiety attack.

Firefighters brought the blaze under control less than two hours after it started. Authorities said no hazardous spread occurred and no workers were missing.

The cause of the explosion remains under investigation.