At least 10 people were shot and six others injured after a man wearing a gas mask opened fire on a moving New York City subway train during rush hour Tuesday morning.

The attack triggered a massive law enforcement response to Brooklyn’s Sunset Park neighborhood and a manhunt for the suspect, officials said.

A Manhattan-bound N train was pulling into the 36th Street Station when shots rang out inside a subway car at about 8:24 a.m., NYPD Commissioner Keechant Sewell told reporters. None of the wounded have life-threatening injuries, and this isn’t being considered an act of terrorism, according to authorities.

“The suspect was in the train car, the shooting began in the train car. As the train was pulling into the station, the subject put on a gas mask. He then opened a canister that was in his bag and then the car began to fill with smoke. After that he began shooting”, - Sewell said during a news conference.

Passengers, including some of the wounded, stumbled out of the train - with a few of them boarding an R train across the platform to get away.