At least 13 people were injured during a rush-hour shooting at a subway station in the New York borough of Brooklyn Tuesday, where authorities said "several undetonated devices" were recovered amid chaotic scenes.

Ambulances lined the street outside the 36th Street subway station, where a New York police spokesperson said that officers responded to a 911 call of a person shot at 8:27 am (1227 GMT).

Unverified video footage posted on Instagram appeared to show passengers tending to bloodied victims lying on a smoke-filled station platform.

The images showed subway staff shepherding panicked passengers, some still clutching their morning coffee cups, off the platform and into the carriages of a stationary train. A sign saying 36th Street can be seen in the background.

An unidentified person can be heard saying that a fire had been set in the train car, and that he saw "at least eight people" shot.

According to NBC, citing NYPD and senior law enforcement officials, a man in a gas mask and orange construction vest may have tossed a smoke canister on the platform to distract the rush hour crowd.

The suspect was still at large, according to Manhattan borough president Mark Levine.

The city's fire department gave a toll of "13 injuries at this time," while ABC News quoted police sources as saying at least five people were shot in the incident.

The police department tweeted that there were "NO active explosive devices at this time."

"Please stay clear of the area" the NYPD tweeted, urging witnesses to contact a police tip line with any information.

The White House said President Joe Biden had been briefed on the incident and was in communication with New York officials.

New York governor Kathy Hochul tweeted that first responders were on the scene and promised regular updates as the investigation unfolds.

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