A doctor has shot dead a former colleague and seriously injured five others after opening fire in a New York City hospital.

The gunman, a former doctor at the hospital, tried to set himself on fire before fatally shooting himself, officials said.

Mayor Bill de Blasio said a female doctor was killed in the attack, adding five others were "fighting for their lives".

A seventh victim sustained a gunshot wound to the leg.

Image: Doctors were targeted in the shooting

Describing the rampage at Bronx-Lebanon Hospital Center as a "real tragedy", Mr de Blasio said it was a "workplace-related matter" and "not an act of terrorism".


Dr Henry Bello, who concealed an assault rifle under a lab coat he was wearing, reportedly resigned from the hospital in 2015 after sexual harassment allegations.

Following the attack, at least one wounded doctor was treated using an emergency fire hose fashioned as a tourniquet, the New York Times reported.

Those wounded were said to be on the 16th and 17th floors, while the lifts were apparently out of service.

Image: Police outside the hospital in New York

According to an ambulance worker, two emergency responders carried a bleeding patient down nine flights of stairs to safety, applying pressure to the man's wound as they descended.

Armed police searched the building floor by floor and at one stage officers could be seen on the roof with their guns drawn.

Patient Gonzalo Carazo said he locked himself in a room for 15 minutes until police came and led him out of the hospital.

"I saw one of the doctors and he had a gunshot wound to his hand," he told WCBS-TV.

Image: Five people were seriously wounded in the attack

"All I heard was a doctor saying 'help, help'".

Garry Trimble said his fiancee, hospital worker Denise Brown, called him from inside the building during the shooting.

"She woke me up and told me there was a situation, somebody's out there shooting people," he said.

"I could hear in her voice she was shaking and about to cry."

According to police records, Dr Bello was arrested in 2009 after two women claimed he tried to look up their skirts with a mirror.

Image: Officers went through the building floor by floor

In another unrelated incident, Dr Bello was held in 2004 after a woman told police he grabbed her, lifted her up and said: "You're coming with me".

A former colleague said Dr Bello sent him a threatening email after resigning from the hospital.

"(Dr Bello) was very aggressive, talking loudly, threatening people," Dr David Lazala said.

"All the time he was a problem."