GREELEY, Colo. (AP) — An explosion at a northern Colorado drilling site injured three workers, including one who was hospitalized with minor injuries.

Windsor Police Sgt. Brian Smith tells The Greeley Tribune the small explosion involving a liquid nitrogen line happened Thursday night, and no fire was involved in the blast.

Smith said he did not have details about the well operator, but the active site had 56 employees on scene.

State regulators will help with the investigation.

No other information was released.

___

Information from: The Tribune of Greeley, Co, http://greeleytribune.com