The Middletown Fire Department on Main Street. City crews are responding to a fire at the Kleen Energy power plant Wednesday afternoon.

MIDDLETOWN — Crews are responding to the Kleen Energy power plant on River Road Wednesday afternoon after a fire was reported.

One fire official said the blaze was believed to be a hydraulic oil fire that started inside a turbine, filling the building with smoke. Fire marshals were on scene investigating the cause as of just before 3 p.m., he said.

The official said local crews as well as ones from Middlefield, Durham, Cromwell and Portland responded to the plant. He said resources from Killingworth, Chester and Haddam also responded.

No injuries have been reported, according to fire officials. 

Police are at the scene to control traffic. 

The plant was the site of a deadly natural gas explosion in 2010 that killed six people and injured dozens of others. Investigators later determined plant workers had been using the gas to clear debris from pipes, when it ignited and exploded.

The explosion resulted in the state banning the use of flammable gas for the procedure, known as "gas blows." 

Peter Yankowski is a breaking news reporter for Hearst Connecticut Media. He previously reported for the Danbury News-Times and, before that, the Ridgefield Press.