It is believed a shooting has been reported at the ICU of Dartmouth-Hitchcock Medical Centre in Lebanon, New Hampshire.
Reports on Twitter suggest one person has been shot but as yet there has been no official confirmation of shots fired.
The hospital has issued an “active shooter alert” however, and patients and staff have been evacuated from the centre.
One employee claimed all workers received an email from the hospital about a “code silver,” which apparently means a person with a weapon, telling them to get out if possible and otherwise to shelter in place.
Images from the scene show patients in wheelchairs and those who need assistance being helped out into a parking lot.
Others have allegedly been evacuated from the building and told to take shelter in a bank on the campus, where they have been locked inside.
Lebanon High School and Hanover Street Elementary School are also under lock down, according to school officials.
In a tweet, Dartmouth College clarified its campus is not on lockdown and classes are ongoing.
The Lebanon Police Department is asking people to avoid the area while roads around the hospital have been closed.
A spokesman for the hospital Mike Barwell said: “Dartmouth-Hitchcock Medical Center in Lebanon is currently locked down following reports of an active shooter in the hospital.
“We are assessing the situation now, and will have more information as soon as it becomes available.
“Lebanon and New Hampshire State police have been alerted and are on-site.”
The office of New Hampshire’s attorney general confirmed they are also responding to the scene.
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