WHAT WE KNOW SO FAR:
Update 10.02pm: The gunman who opened fire at a New York City hospital, killing at least one person, was a doctor who used to work there, a police official said.
Dr Henry Bello walked into Bronx Lebanon Hospital at about 2.50pm on Friday with a rifle concealed in his lab coat and opened fire, killing at least one person and injuring six others, before apparently killing himself.
Dr Bello was listed on the hospital's website as a family medicine physician.
It is not clear when he left the hospital.
Update 9.46pm: A man pulled a rifle from under his white lab coat and opened fire inside a Bronx hospital today, killing at least one person and wounding others before apparently taking his own life, police in New York said.
The gunfire broke out at 2.50pm inside the Bronx Lebanon Hospital, bringing police cars and fire vehicles rushing to the scene and sending officers onto the roof with their guns drawn as people inside the building were told to hide.
Officers went floor by floor looking for the gunman and reported just before 4pm that the shooter was dead inside the building.
A law enforcement official told The Associated Press that the gunman apparently killed himself.
According to the law enforcement official, the shooter was wearing a lab coat and had the rifle concealed.
The official was not authorised to discuss the still-unfolding investigation and spoke on condition of anonymity.
Update 9.39pm: The gunman at the Bronx Lebanon Hospital in New York City killed one person and injured six, and was a former employee at the facility, The Associated Press has reported.
Update 9.28pm: The Associated Press is quoting a law enforcement official as saying that the New York hospital gunman killed at least one person before apparently turning the gun on himself.
Update 9.04pm: A New York City police spokesman has said that a gunman inside the Bronx Lebanon Hospital has been shot dead.
Update 8.55pm: Police say at least two people have been shot at a New York City hospital and the gunman is still at large.
The gunfire broke out at 2.50pm local time on Friday inside the Bronx Lebanon Hospital in the Bronx.
Police could be seen on the roof of the building, at one point, with their guns drawn.
Update 8.48pm: The New York Times is reporting that at least three doctors were shot inside Bronx-Lebanon Hospital Center in the Mount Hope area of the Bronx, according to a Fire Department official.
The condition of the doctors is not known.
The Times further reports that in a radio transmission, police described the gunman as a tall, thin man wearing a blue shirt and white lab coat.
Multiple people have been shot at a New York City hospital, police said.
The gunfire broke out at 2.50pm local time today inside the Bronx Lebanon Hospital in the Bronx.
Police had no immediate information on whether anyone was killed.
Television images showed the hospital surrounded by police cars and fire vehicles.
It is being reported the shooter or shooters are still at large, and may still be in the hospital.
Bronx-Lebanon Hospital Centre describes itself as the largest voluntary, not-for-profit health care system in the south and central Bronx.
The 120-year-old hospital claims nearly 1,000 beds spread across multiple units.
Its emergency room is among the busiest in New York City.
The hospital is about a mile and a half north of Yankee Stadium.