Several people injured after explosion at the Blue Rhino gas plant in Florida

UPDATE: THREE people are in a critical condition with severe bus after a series of explosions rocked a propane gas plant in Florida.

All workers at the Blue Rhino propane gas plant have been accounted for after as many as 15 were initially feared killed, authorities say.

John Herrell of the Lake County Sheriff's Office said no fatalities had been reported after explosions hit the plant about 11pm local time.

Seven people were injured and transported to local hospitals.

ABC News reports three men have been taken to the Orlando Regional Medical Center with bus and are in a critical condition. Another victim is in a stable condition in intensive care at Ocala Regional Hospital.

Herrell earlier had said 15 of the plant's 24 night shift workers were unaccounted for after the blasts, but all were later found safe.

Emergency crews are still on the scene and nearby residents have been evacuated. A 1.6km exclusion zone has been set up around the plant.

Aerial footage of the scene showed fires still buing over a large area, shooting large flames and plumes of smoke into the night sky. Emergency crews could also be seen massing nearby.

Resident Ashley McCormick from the neighboring town of Mount Dora told ABC News she could see the fire from several kilometres away.

We've probably heard close to 100 or more [explosions]. I mean there are hundreds of propane tanks out there," she said. "You could hear the explosions just…one after another and then after it would explode, a fireball would shoot up into the sky."