At least 10 people were shot and a gunman remains at large after an attack on a Brooklyn subway train left riders in panic Tuesday morning, city officials said.

The shooting occurred before 8:30 a.m. on a Manhattan-bound N train in Brookyn’s Sunset Park neighborhood, Police Commissioner Keechant Sewell said at an afternoon news conference.

The train was waiting to enter the 36th Street station when a man put on a gas mask and opened a canister before the train began filling up with smoke and the man began firing, Sewell said. The shooter, whom Sewell described as a Black male with a heavy build, was wearing a green construction vest and a gray sweatshirt, she said.

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