(Editor's Note: This article was updated at 3:30 p.m. on Saturday, Sept. 1.)
An anonymous bomb threat led to a lockdown of on Saturday afternoon and the investigation remains ongoing.
According to a press release, at 1:22 p.m. hospital staff reported to police that they had received an anonymous call informing them of an explosive device located within a secure area of the hospital.
Both Melrose Police and responded and the hospital was advised to follow their protocol regarding evacuation of the building, according to the press release.
"Additional security measures were set in place, including a limited access, and lockdown of certain areas of the hospital," the press release said. "The area that is involved is a secure area, with entry control systems in place. It can only be accessed by individuals assigned to that particular floor and ward of the hospital."
Melrose Police established a command post and are coordinating with State Police; an explosive detecting K9 unit is also responding to the hospital.
Initial public safety transmissions on Saturday said that the hospital was on lockdown and ambulances were being diverted, with Melrose Police officers blocking entryways.