A family doctor has opened fire with an assault rifle at one of New York's busiest hospitals, killing a woman and shooting six others, before apparently taking his own life.
NBC News, citing sources, identified the gunman as Dr Henry Bello, a 45-year-old family medicine doctor who used to work at the hospital.
The medic, who was dressed in a white doctor's coat, remained at large for around an hour as armed police descended on Bronx-Lebanon Hospital Center.
The rampage sparked a major security fear at the hospital, which houses around 1,000 patient beds, before Bello's death was confirmed.
The female victim was found dead on the 17th floor of the hospital, while all of the injured victims were located on the 16th floor.
Five had suffered serious injuries while one suffered a gunshot wound to the leg, police confirmed at a news conference outside the hospital.
A police commissioner announced "one shooter" was dead before another law enforcement official said it was understood the suspect had killed himself.
The Bronx hospital had gone into lockdown as the surrounding streets were gridlocked by officers after the shootings shortly before 3pm local time.
A fire official earlier told the New York Times at least three doctors were among those shot, with their condition unknown.
Staff said police removed people floor by floor while officers were seen on the multi-storey hospital's roof, with smoke also seen on the 16th floor.
The New York Times said the gunman was described as a "tall, thin man wearing a blue shirt and white lab coat" in police radio transmission.