Lebanon police in New Hampshire told Fox News they received "reports of shots fired", but did not confirm there was a shooter in the building.
According to a staff alert from Dartmouth-Hitchcock Medical Center, the campus is now under a code silver.
Rhode Island State Police say the suspect taken into custody following reports of an active shooter at New Hampshire's largest hospital is a Rhode Island resident. Police flooded the scene and reports of a suspect in custody started coming in about an hour after the first reports of the incident.
Dartmouth College also clarified its Hanover campus was not on lockdown and classes are going on as scheduled; however, it asked people to not go back to the Lebanon campus and that a family and visitor center is being set up.
Several witnesses driving along Interstate I-89 reported seeing heavy State Police presence at all exits.
Nearby Dartmouth College said on Twitter that police were searching for a 6-foot, 1-inch (1.85 m) tall man with salt and pepper blonde hair who was wearing a red camouflage shirt.
The active-shooter alert forced authorities to issue evacuation and shelter-in-place orders.
This a developing story.
With state police and the attorney general are responding to the incident but are only go so far as to call the incident an "active investigation".