Updated July 01, 2017 08:18:19

Photo: Emergency crews had been kept from going inside the hospital while the shooter was a large. (AP: Joseph Frederick)

A former employee of a New York City hospital returned with an assault rifle hidden under his white lab coat and opened fire, killing one doctor and wounding six other people before apparently taking his own life.

The gunfire broke out at 2:50pm (local time) inside the Bronx Lebanon Hospital, bringing police cars and firetrucks rushing to the scene and sending officers onto the roof with their guns drawn as people inside the building were told to hide.

The assailant, wearing a white, medical-style lab coat and armed with an assault rifle, stalked the 16th and 17th floors of the hospital, and apparently tried to set himself on fire at one point, officials said.

Officers went floor by floor looking for the gunman and later reported that the shooter was dead inside the building.

He was identified by law enforcement officials as Dr Henry Bello, a family medicine physician at the hospital.

It was not immediately clear why he was no longer working at the hospital and there was no immediate word on a motive.

"One doctor is dead and there are several others who are fighting for their lives right now," New York City Mayor Bill de Blasio said.

The Mayor characterised the shooting as an "isolated incident" that appeared to be "workplace-related".

The 120-year-old hospital has nearly 1,000 beds and one of the busiest emergency rooms in New York City.

AP/Reuters

Topics: crime, united-states

First posted July 01, 2017 06:42:23