An explosion at an ethanol plant in southern Minnesota Sunday morning injured two employees, authorities said.

Freeborn County sheriff's deputies responded to the Poet ethanol plant in Glenville, south of Albert Lea, around 3 a.m.

Four employees were at the scene at the time of the incident, but only two were injured.

The two injured workers were treated at the scene before being taken to Mayo Clinic Health Systems of Albert Lea, according to the Sheriff's Office.

The cause of the explosion, which damaged the building, is under investigation.

Several agencies that assisted the Freeborn County Sheriff's Office were the Glenville, Hayward, Myrtle and Albert Lea Township fire departments, Freeborn County Emergency Management, Albert Lea Police Department and the State Fire Marshal.

The Poet biorefining plant in Glenville produces 42 million gallons of ethanol ­annually, according to its website.

Karen Zamora