The Boston Police Department reports arresting two of the seven or eight teens they say tried to rob a man at knifepoint outside the KFC at 481 Washington St. around 10:20 p.m. on Friday.

According to police, the man was walking past the restaurant when the teens, both males and females, demanded his phone and wallet as one of their number pointed a knife at the man.

Instead, police report, the man swung a plastic bag containing three cans of beer at the group, which apparently made them rethink their plans and they left.

Police say officers arrived on scene just in time to see the teens walking away:

"As officers approached the group, several attempted to flee on foot, but were quickly detained at Claybourne and Park Street. A bring back procedure was conducted and as a result, witnesses on scene positively identified two of the youth suspects. A black pocket knife was seized as evidence."

A 17-year-old from Dorchester and a 15-year-old from Randolph were charged with being delinquent for armed robbery. The 15-year-old was also charged with being deliquent for resisting arrest and assault and batter on a police officer, police say.