Fourteen people were arrested Tuesday afternoon when police confronted an unruly teenage mob in Center City, authorities said.
About 3:50 p.m., 100 to 200 young people were seen running near 15th and Chestnut Streets, Police Chief Inspector Cynthia Dorsey said.
Officers tracked the crowd and tried to bring it under control as it moved between nearby blocks, Dorsey said.
Two girls were arrested for fighting, Dorsey said.
"We don't know at this point if they were here to watch a fight or a fight spontaneously broke out," said Dorsey, a city officer assigned to the Philadelphia School District's Office of School Safety.