No hazardous materials were released, Shakopee Fire Chief Jake Theisen said.

Dozens of firefighters and emergency workers rushed to an explosion at a biomass plant south of Minneapolis on Thursday, but no one was hurt and no hazardous materials were released, officials said.

Authorities got a 911 call around 12:40 p.m. from Koda Energy LLC, which shares a complex with Rahr Malting Co. along the Mississippi River in Shakopee.

Koda produces energy from oat hulls and wood chips, byproducts of malting, and the explosion happened in two of its silos, the company said.

Seven Koda workers on the scene were safely evacuated, and the company said everyone is accounted for. Firefighters and emergency crews from eight agencies responded, but no one was hurt, Scott County spokeswoman Lisa Kohner said.

The city initially advised people living within a mile of the complex to stay in their homes, but the all-clear was sounded by mid-afternoon. No hazardous materials were released, Shakopee Fire Chief Jake Theisen said.

Crews had the three-alarm fire contained by 3 p.m., but they were expected to stay on the scene into the evening.

The fire caused damage to two biomass fuel silos, their conveyor system and a truck unloading facility, Koda said. A smoldering fire in the two silos is expected to burn itself out, the company said.

"I heard a boom and looked out my window and saw a shock wave coming toward my building," Amy Johnson, 26, who lives in an apartment down the street, told the Star Tribune. "It hit my window, and the whole apartment building just shook. It was like something out of a movie."

Koda is a partnership between the Shakopee Mdewakanton Sioux Community and Rahr, a family owned business that began in 1847. The combined heat and power plant opened in 2009 and provides energy for Rahr, which produces and distributes malt and industry-related brewing supplies, and the nearby Mdewakanton reservation.

The cause of the blast is under investigation. No damage estimates are available. Koda said it did not know when it would resume operations.

Shakopee is about 14 miles south of Minneapolis.