A shooting at a concrete machine factory in Maryland left three people dead and one injured on Thursday, a local law enforcement agency said.

The shooting happened around 2:30 PM at the Columbia Machine factory in Smithsburg, the Washington County Sheriff’s Office confirmed.

The shooter then fled the scene before police arrived, they said, after which state troopers tracked him down and stopped him. He then shot at troopers, hitting one of them.

The shooter and the trooper were both injured and taken for medical treatment, the sheriff's office said.

Maryland Governor Larry Hogan also confirmed at an earlier press conference that the trooper had been shot in the shoulder after shooting back at the gunman.

The Baltimore sector of the Bureau of Alcohol, Tobacco, Firearms and Explosives said on Twitter that special agents from their office were helping local police.

Maryland Sen. Chris Van Hollen tweeted that he was closely monitoring the shooting and in contact with local police.

And U.S. Rep. David Trone, a Maryland Democrat, tweeted earlier that his office was in contact with authorities in the area and actively monitoring the shooting in Smithsburg. News photographs showed a large law enforcement presence, including emergency vehicles at the scene.

Smithsburg, a community of nearly 3,000 people, is located about 75 miles northwest of Baltimore not far from the Maryland line with Pennsylvania.