NEW YORK — Ten people were shot Tuesday at a New York City subway station during a morning rush-hour attack that left wounded commuters bleeding on a train platform and police searching for the shooter.

Fire personnel responding to reports of smoke at the 36th Street station in Brooklyn’s Sunset Park neighborhood at around 8:30 a.m. found multiple people with injuries.

According to multiple law enforcement sources briefed on the investigation, preliminary information indicated that the suspect who fled was a man wearing a construction vest and a gas mask.

Photos and video from the scene showed people tending to bloodied passengers lying on the floor of the station and the air filled with smoke. Fire and police officials were investigating reports that there had been an explosion, but the police department tweeted that there were “no active explosive devices at this time.” Multiple smoke devices were found on the scene, said mayoral spokesperson Fabien Levy, who confirmed the initial shooting injury count.

At least 11 people were being treated at two local hospitals.

“My subway door opened into calamity. It was smoke and blood and people screaming,” eyewitness Sam Carcamo told radio station 1010 WINS, saying he saw a giant billow of smoke pouring out of the N train once the door opened.

A bystander video shows people lying on the subway platform amid what appeared to be small puddles of blood, as a loudspeaker announcement told everyone on the smoke-hazy platform to get on a train. Inside a subway car, a person lay on the floor, encircled by others. Outside the station, a police officer yelled, “Let’s go! Get out of the way!”

Danny Mastrogiorgio, of Brooklyn, had just dropped his son off at school when he saw a crush of passengers, including multiple wounded, running up the subway stairway in panic. At least two had visible leg injuries, he said.

“It was insane,” he told The Associated Press. “No one knew exactly what was going on.”

One witness said it was smoky in the station. She saw a wounded teenage boy in the subway station.

“You can clearly see the bullet in his knee,” she told PIX11 News.

Once she came out of the station, she saw more injured people outside.

“I was thankful that I was not with my brother because I was dropping him off before,” she said.

Allan Lee was running his business, Cafe Nube, when a half-dozen police cars and fire vehicles suddenly converged on the block.

“Then they started ushering people that were on the block to the adjacent block and then closed off the subway entrance” near the cafe’s door, he told the AP. When he noticed bomb squad officers and dogs, he was certain it was no everyday subway problem.

Police officers were canvassing Fourth Avenue, the station’s cross-street, asking witnesses whether they were on the train. A sea of emergency lights was visible from at least a dozen blocks away, where a police cordon was set up.

The shootings come as New York City has faced a spate of shootings and high-profile incidents in recent months, including on the city’s subways. One of the most shocking was in January when a woman was pushed to her death in front of a train by a stranger.