At least six people have been killed in a vehicle attack and shooting near the 9/11 memorial site in New York, according to Sky sources.
Witnesses told local media a vehicle drove down a popular bike path and struck pedestrians and cyclists before the shooting started.
At least 15 people were hit by the van, with law enforcers warning commuters to expect many emergency services workers in the area.
Reuters is reporting that the incident is being treated as a terrorist attack.
A large number of police vehicles could be seen near West Street and Chambers Street, which is near a community college, a high school and a few blocks north of the 9/11 memorial site, where the World Trade Center once stood.
Law enforcement sources told Sky News that the van was driven more than 10 blocks from Houston Street down to Chambers Street along the west side highway on a busy bike path.
Photos from the scene showed a badly damaged Home Depot rental pickup truck in the middle of the road.
When the vehicle struck a pole near Chambers Street, officers and witnesses said the man got out and started screaming and shooting.
A 14-year-old student from the nearby Stuyvesant High School told the New York Post: "What happened was there was a car crash… he came out of one of the cars. He had two guns.
"He was running around Chambers and somebody started to chase him.
"I heard four to six gunshots - everybody starts running."
An Uber passenger who was riding along the West Side Highway near the World Trade Center says he saw several bleeding people following the incident. It is unclear whether anyone was shot.
A witness says the truck had also collided with a small bus and one other vehicle.
The man was then shot by police, but has been taken to hospital and is expected to live.
NYPD said one person had been arrested and they were not looking for anyone else.
The incident appeared to have echoes of the London Bridge terror attack in June - when Islamic State terrorists used a Hertz rental van hired from a B&Q hardware store to mow down pedestrians before stabbing a number of victims nearby.
