Police were investigating reports of a person with a gun on campus at UMass Amherst while the school went on lockdown for approximately two hours.

"A handgun was shown but not fired during the incident, which occurred about 5:17 p.m. in Pierpont Hall on Fearing Street in the Southwest Residential Area," a statement from UMass Amherst posted on their Facebook late Thursday evening said. "The assailants are not believed to be UMass students. The male victim suffered a laceration to the head and is being treated at Cooley Dickinson Hospital in Northampton. UMass Police said the assault is not believed to be random."

News of the incident was first revealed to students Thursday evening as the university broadcast an order to "shelter in place" to all students and staff.

"ALERT! UMass Amherst police report one or two hostile armed persons in Pierpont Hall. Police at the scene haves established a perimeter. All persons are directed to shelter in place," the college posted on Facebook.

"One suspect is a white male wearing a dark-colored shirt and a gold chain. Second suspect described as a white male in gray sweatshirt. Police are interviewing witnesses," the university posted just after 6:30 p.m., posting at 6:40 p.m., "Continue to shelter in place. More details as they become available."

Text messages sent to UMass students said a handgun "was shown but not fired" by the first gold-chain wearing suspect.

At 7:13 p.m. the shelter in place order was lifted.

"Shelter in place order has been lifted. Please resume normal activities. More information will be provided as it becomes available," the University said on Facebook.

The University said more updates would be provided soon as the investigation went forward.