Newly surfaced cell phone footage shows confusion and fear after a gunman fired shots at Harvard Square MBTA station sending crowds fleeing.

Transit police in Boston are investigating the shooting on a subway platform on Sunday and are hunting a man in a ski mask who was seen running from the station.

The shooter targeted a specific individual who escaped unharmed.

Authorities are reviewing footage and eyewitness accounts as they search for the suspect, who remains at large.

Pablo Escobar, 38, a construction worker in Cambridge, Massachusetts, was traveling to Quincy when the panic unfolded.

"I was walking to the train station when I heard a noise. When I went down, I saw a lot of people coming out," Escobar said. "

His video captures passengers shouting and sprinting up escalators and as chaos erupted in the station.

"When I started recording, there were a lot of people asking what's going on," he added."

The shooting occurred around 2:12 p.m. on April 20, when a man fired multiple rounds on the southbound Red Line platform.

No injuries were reported, but the incident triggered a massive police response and temporary shelter-in-place orders for Harvard University.

Escobar described the disorientation that followed the gunfire.

"A lot of people looked nervous and others didn't know what's going on," he said. "A few minutes later, a lot of police came to the station along with a lot of reporters."

Authorities cordoned off turnstiles and searched the platform as the shooter remained at large.

"I felt safer when I saw the police," he said. "That kind of thing shouldn't happen in that place. I mean, Harvard is supposed to be a secure place."

The MBTA shut down Harvard Square station for hours, disrupting Red Line service during the busy Boston Marathon weekend.

Transit Police continue to review surveillance footage and eyewitness accounts, including Escobar's video, to identify the shooter.

Images of a person of interest were released, but no arrests have been made.