Manhunt under way for gunman in NYC subway shooting that injured at least 20

This photo provided by Will B Wylde, a person is aided in a subway car in the Brooklyn borough of New York on Tuesday (April 12). A gunman filled a rush-hour subway train with smoke and shot multiple people on Tuesday, leaving wounded commuters bleeding on a Brooklyn platform as others ran screaming, authorities said. Police were still searching for the suspect. (Will B Wylde via AP)

NEW YORK: Police mounted an intense manhunt on Tuesday (April 12) for a gunman who set off two smoke bombs and opened fire in a New York subway car, injuring at least 20 people in a morning rush-hour attack that prompted new calls to fight a surge of violence in the city's transit system.

Police said the gunman was believed to have acted alone and immediately fled the crime scene. The attack unfolded as a Manhattan-bound subway train on the N line was pulling into an underground station in Brooklyn's Sunset Park neighborhood.