Transit Police report arresting four teens - all 15 or 16 - on charges related to an attack on a Silver Line bus at Washington and Herald streets in the South End around 10 p.m. on Tuesday, May 14.

The four first tried to rob a 68-year-old man of his phone, but when he refused to yield, "the juveniles began to assault/beat the victim," police say.

Police add officers were able to get to the scene quickly enough to arrest all four on charges of being delinquent for assault with intent to rob, assault and battery with a dangerous weapon - shod foot - and assault and battery on a person over 60. Their names were not released because of their ages.