Dartmouth-Hitchcock Medical Center, New Hampshire's largest hospital, reported on its Facebook page that the building was on lockdown after reports of an active shooter just before 2 p.m. local time on Tuesday.
Authorities were dispatched at the hospital and sent out an announcement that warned people to avoid the area, and traffic was stopped on a route leading to the hospital.
"Dartmouth-Hitchcock Medical Center in Lebanon is now locked down following reports of an active shooter in the hospital", media relations manager Mike Barwell said in a statement.
Manchester United's Ander Herrera patient despite lack of game time
Ander Herrera has a stark warning for his Manchester United team-mates, insisting it would be a mistake to underestimate their Champions League opponents.
The hospital confirmed via Twitter earlier in the afternoon that the campus was "locked down following reports of an active shooter in the hospital" and said officials were assessing the situation. The hospital was under lockdown and it wasn't clear if that was lifted.
One person is in custody after an active-shooter report at a New Hampshire hospital, according to the city's website. Updates will be provided as more information becomes available.
Police flooded the scene and reports of a suspect in custody started coming in about an hour after the first reports of the incident.