Authorities say a police officer has been shot while responding to a shooting at a plasma donation centre in southwestern Michigan.

Kalamazoo police say the officer's injuries aren't life-threatening. Lisa Walterhouse, an employee at the downtown plasma center, tells the Kalamazoo Gazette that police responded Tuesday after a former employee entered the building and fired shots.

Walterhouse says the gunman told people to call 911. She says, "Then we ran."

Police say there's "no active threat" to the public. The statement didn't mention anything about the gunman. A late afternoon news conference is planned.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)