Three teenagers from Quincy are accused of a “brutal and unprovoked attack” on a group of Duxbury teens at the Kenmore Square MBTA station, leaving the victims with facial injuries, police said.

An 18-year-old and two 17-year-olds have been arrested and charged in connection with the alleged attack from earlier this month, according to the Suffolk County DA’s office.

MBTA Transit Police responded to the Kenmore T station for a reported assault on Friday, May 10, at around 10:14 p.m. after the Sox game. Police officers spoke with the four teens from Duxbury, who said they had been attacked by a group of people they didn’t know.

Three of the teens were bleeding from their mouths, and the fourth had blood on his clothing and on his knuckles, police said.

One of the alleged attackers had lifted his sweatshirt and shown a knife in his waistband, the victims told police. They were then reportedly punched and thrown to the cement floor. One of the victims reported that his jacket and sneakers were stolen.

MBTA police recovered the jacket nearby, and it had been destroyed, police said.

Police then reviewed T station video and cell phone video showing the victims being attacked by 18-year-old Aidan McGuinness, the two juveniles and two others, who have yet to be identified. The video corroborated the victims’ account of the attack. The victims also provided descriptions of the alleged attackers.

In the video, McGuinness is reportedly seen pushing one of the victims while the victim is being struck by another attacker. McGuinness and others are seen striking the victim multiple times on the ground. McGuinness also reportedly took the victim’s jacket.

Police were helped in identifying the suspects by a person who saw a Snapchat video of the attack sent to about 60 people. The viewer recognized McGuinness and other attackers as high school students from Quincy.

“These individuals may have thought they could launch a brutal and unprovoked attack on a group of young people and get away clean, but the tenacity of transit police combined with help from the victims, the public, and video and social media evidence proved them wrong,” Suffolk DA Kevin Hayden said.

“These victims endured a terrifying experience and suffered serious injuries while doing nothing more than enjoying an evening in Boston,” the DA added. “Their attackers will answer for their actions.”

McGuinness was charged with unarmed robbery and assault and battery causing serious bodily injury. The judge imposed $1,500 bail and ordered McGuinness to stay away from the victims.

One of the 17-year-olds was charged with two counts of assault by means of a dangerous weapon (knife), one count of assault and battery causing serious bodily injury, one count of unarmed robbery and one count of assault and battery. The other juvenile was charged with assault and battery with a dangerous weapon (cement floor), assault and battery causing serious bodily injury and unarmed robbery.

The judge ordered both juveniles held on $200 bail, and also ordered them to stay away from the victims and stay away from Kenmore MBTA station.