LOS ANGELES, July 29 (Xinhua) -- Three people are missing after an explosion at a plant on Tuesday in Fremont, U.S. state of Nebraska, local authorities and news outlets said.

Troopers, along with multiple fire and police agencies are on the scene of a building fire near East Cloverly Road and South Union Street in Fremont, Nebraska State Patrol said on Facebook.

Fremont Mayor Joey Spellerberg told ABC-affiliated KETV television station that three people were inside the plant when it exploded just before noon.

The blast was reported a few minutes before noon at the location where wood pellets for fuel are made by Horizon Biofuels, Inc., authorities said.

According to official data, the company employs 10 people and is one of three commercial pellet plants in Nebraska, which produces pellets from waste wood.

"We will continue to closely monitor the explosion in Fremont in coordination with local responders, law enforcement, and state partners," Nebraska Governor Jim Pillen said on his social media account on X.