Four people have been killed in a shooting incident in Manhattan, New York. This comes after a man walked into an office building and shot several people, including an off-duty police officer, before taking his own life.

The New York Police Department’s Commissioner Jessica Tisch later said the scene had been contained.

The 27-year-old attacker is from Las Vegas.

A picture of the gunman was quickly all over social media, walking confidently across the office plaza, sunglasses on and firmly gripping a long gun to his side.

He reportedly entered 345 Park Avenue during rush hour, around 6 pm, when evening foot traffic was in full flight.

The shooting is said to have occurred inside the building, resulting in a massive law enforcement response within minutes, shutting down the scene for blocks while disrupting the rush hour.

The officer killed was reportedly working security for the building on his day off, while the suspect is reported to have died from a self-inflicted gunshot wound.

The building contains the offices for Blackstone, the National Football League (NFL) and KPMG.