NEW YORK -- A gunman killed four people and injured six others on early Monday evening before shooting himself dead inside an office building in Manhattan, New York City.

The 27-year-old gunman named Shane Tamura opened fire around 6 p.m. (2200 GMT) and died from "an apparently self-inflicted injury," CNN reported. The information was later confirmed by Mayor Eric Adams.

Earlier, New York Police Commissioner Jessica Tisch said on X, "At this time, the scene has been contained and the lone shooter has been neutralized."

One of the victims was an off-duty New York Police Department officer, while the other three were civilians, local media reported.

The gunman reportedly came from Las Vegas as authorities found a vehicle with Nevada plates registered to Tamura at the scene, with a rifle case inside, according to the New York Post.

The shooter's motive is unclear until now.