"Troopers are currently investigating a shooting at New Hampshire State Hospital in Concord. There are multiple victims," New Hampshire State Police said on Friday evening.
In a separate statement, the New Hampshire Homeland Security and Emergency Management said that while the scene is still active, the suspected shooter is dead.
"The situation at New Hampshire Hospital has been contained. The scene remains active. The suspect is deceased," the statement said.
Video footage has since surfaced of the police response.
New Hampshire Gov. Chris Sununu earlier indicated the hospital campus was cleared by officials.
Reports have detailed that calls were received by police just after 4 p.m. local time, and that the scene was brought under control within a span of 30 minutes.
Several law enforcement agencies are said to have responded to the scene.