EMERGENCY services have evacuated an area around a solvents factory on an industrial estate in Arganda del Rey, just 16 miles from Madrid.
The area has been rocked by explosions and 15 people are reported injured, three of them seriously.
112 Comunidad Madrid have posted images on Twitter of thick plumes of smoke towering over the site.
Firefighters are at the scene but, as yet, the cause of the blaze in not known.
The Twitter page also posted footage of firefighters combating the blaze.
— 112 Comunidad Madrid (@112cmadrid) May 4, 2017