India, July 29 -- At least four people, including a police officer, were killed after a gunman opened fire after entering a Midtown skyscraper in New York on Monday.

The shooter was identified as 27-year-old Shane Tamura.

According to reports, Tamura died due to self-inflicted injury.

The 44-year-old attacker barged into the 44-storey building, which also houses major corporate offices like Blackstone and the NFL.

Armed with a rifle, the attacker opened fire at around 6:30 p.m. during the evening rush, cops and law enforcement sources told The New York Post.

Tamura, who authorities said had a "mental health history," unleashed his rampage after setting foot in the lobby, first gunning down officer Didarul Islam, NYPD Commissioner Jes...