A man opened fire at a manufacturing plant in the US state of Maryland, killing three people and injuring a fourth.

Police said the shooting took place in Smithsburg, about two hours from Washington DC, on Thursday afternoon. They said three male workers were found dead and another male worker seriously injured when police officers arrived at the scene.

Authorities said the suspect and police exchanged gunfire at a location about 8 kilometers from the plant, after the suspect fled from the plant in a vehicle. The suspect was taken into custody.

Police said the suspect is a 23-year-old man who worked at the plant. They said he was injured and is being treated at a hospital.
Last month, a gunman shot and killed 21 people, including 19 children, at an elementary school in Texas.
Congress is discussing legislation to tighten gun control in the United States.