Television footage showed smoke billowing out of the windows of the building, with firefighters helping those trapped in the upper floors to escape as hundreds watched.
Police broke windows of the building to help rescue those inside "and got the injured admitted in the hospital," a police statement said, adding that 12 injured were admitted in a local hospital.
The fire broke out in the first floor of the building that houses the office of a surveillance camera manufacturing company, police said.
The building, which rents out office space, is near a railway station in western Delhi suburb Mundka and is about 23 kilometres away from the national capital New Delhi.
More than 50 people have been rescued and firefighters are working to control the fire, the police said, adding that ambulances were also on site.
"More than 30 fire tenders of fire brigade were pressed into service to control the fire," the police said.
