50 Belmont is a three-story building with six apartments and 48 Belmont is a one-story apartment.
All of the residents have been evacuated from the buildings, and none of them were seriously injured.
All of the firefighters were pulled out of the buildings because of the intensity of the flames.
One firefighter ran out of oxygen in the building, but managed to escape.
Three firefighters were treated for heat exhaustion and smoke inhalation.
They all went to the Jersey City Medical Center for treatment.
The Fire Director says most of the fire has been knocked down and is being brought under control.
The cause of the fire is under investigation.