A person opened fire inside a Midtown Manhattan skyscraper housing the NFL headquarters and offices of several major financial firms, including hedge fund giant Blackstone, injuring several people before the suspect was "neutralized," New York City officials said.

Police did not immediately make details of the shooting public, but a law enforcement source told Reuters that one New York Police Department officer was killed, two civilians were struck by gunfire and the suspect was believed to be dead.

The source said the information was preliminary, and the condition or extent of injuries sustained by the two civilians was not immediately known.

New York Mayor Eric Adams said in a video message posted on X there were "multiple injuries" in the shooting.

The New York Post newspaper, citing unnamed police sources, reported that a gunman wearing a bullet-resistant vest and carrying an AR-style rifle had opened fire inside the Park Avenue skyscraper, wounding a police officer and a bystander. The Post reported they were in critical condition.

The gunman, the Post reported, had barricaded himself inside the office tower, possibly on the 32nd floor of the building.

A short time later, New York Police Commissioner Jessica Disch said on X: "At this time, the scene has been contained and the lone shooter has been neutralized."

The suspect died from what was believed to be a self-inflicted injury and was tentatively identified as a 27-year-old man from Las Vegas, CNN reported, citing multiple law enforcement officials.

CNN said police shared a photo of the suspect walking into the building carrying a rifle. Preliminary checks of the suspect's background did not show a significant criminal history, the report added, citing officials.

The skyscraper at 345 Park Avenue houses a number of financial firms, including Blackstone, the world's largest hedge fund, as well as KPMG and Deutsche Bank, along with the NFL headquarters.

A large police presence converged on the area around the tower, according to Reuters journalists near the scene.

The FBI said agents from its New York field office were also responding to provide support at the scene.