PHILADELPHIA (AP) — Philadelphia police say surveillance video should enable them to make more arrests in attacks by two flash mobs over the weekend.

The attacks began at about 7 p.m. Saturday in the city's central business district. Police say one group exited a club and attacked an unidentified couple walking on the street.

Officials say a Southeastern Pennsylvania Transportation Authority police officer who was trying to help break up the crowds was punched and kicked by a 16-year-old girl. She was arrested and charged with assault on police. A 14-year-old boy was also charged with assault and resisting arrest.

A pizza shop owner says two of his delivery men were attacked and a pizza was stolen. He says one man had a broken nose and the other suffered a black eye.