At least eight people have been killed after a rented van drove on to a New York bicycle path in an incident that is being treated as possible terrorism.
The driver of the rented Home Depot van emerged from the vehicle screaming, holding two imitation firearms.
Police say the man was shot by officers and is in custody.
At least nine people were injured in the incident near the World Trade Centre, and the White House said President Donald Trump had been briefed.
New York mayor Bill de Blasio confirmed that it was being treated as a terrorist incident.
“This was an act of terror and a particularly cowardly act of terror aimed at innocent civilians,” he told a press conference.
Mr de Blasio also praised the NYPD officer who “stopped this from continuing”.
White House spokeswoman Sarah Huckabee Sanders said the president and New York native has been briefed by White House chief of staff John Kelly and “will be continually updated as more details are known”.
She said: “Our thoughts and prayers are with all those affected.”
Police said the vehicle entered the cycle path on West Street a few streets from the World Trade Centre memorial and struck at least 15 people, leaving mangled bicycles behind. At least two bodies could be seen lying on the path.
A man who was riding in an Uber along the West Side Highway near Chambers Street said he saw several bleeding people on the ground.
Another witness said the truck had also collided with a small bus and one other vehicle.
Tom Gay, a school photographer, was on Warren Street and heard people saying there was an accident.
He went down to West Street and a woman came around the corner shouting: “He has a gun! He has a gun!”
Mr Gay said he stuck his head around the corner and saw a slender man in a blue track suit running southbound on West Street holding a gun.
He said there was a heavyset man pursuing him.
He said he heard five or six shots and the man in the tracksuit fell to the ground, gun still raised in the air.
He said a man came over and kicked the gun out of his hand.
Uber driver Chen Yi said he saw a truck plough into people on the cycle path. He said he then heard seven to eight shots and then police pointing a gun at a man kneeling on the pavement.
“I saw a lot of blood over there. A lot of people on the ground,” he said.
His passenger, Dmitry Metlitsky, said he also saw police standing near a man who was on his knees with his hands up, and another man bleeding on the ground nearby.
He said the truck had also collided with a small school bus and one other vehicle.
The condition of the attacker was not immediately disclosed.
The 4×4 crashed into a vehicle, after which the driver displayed “imitation firearms” and was shot by officers.
An NYPD statement said: “The vehicle continued south striking another vehicle. The suspect exited the vehicle displaying imitation firearms and was shot by NYPD.”
Earlier a vehicle entered the West St. pedestrian/bike path a few blocks north of Chambers St.
— NYPD NEWS (@NYPDnews) October 31, 2017
The vehicle struck multiple people on the path. There are several fatalities and numerous people injured.
— NYPD NEWS (@NYPDnews) October 31, 2017
The suspect is in custody. This is preliminary, more information to follow.
— NYPD NEWS (@NYPDnews) October 31, 2017
One person is in custody and the NYPD say its investigation is “ongoing”, with people urged to avoid the Chambers Street and West Street area.
Due to police activity, avoid the area of Chambers Street/West St.
One person is in custody. Expect many emergency personnel in the area. pic.twitter.com/rSECr0LRCN— NYPD NEWS (@NYPDnews) October 31, 2017
Earlier spokesman for the New York City Police Department, J Peter Donald, said: “We are responding to reports of shots fired in lower Manhattan. More details when they’re available.”
We are responding to reports of shots fired in lower Manhattan. More details when they’re available
— J. Peter Donald (@JPeterDonald) October 31, 2017
NBC News: A picture from the scene of the incident in lower Manhattan New York following reports of a shooting. Courtesy @NYPDSpeechley pic.twitter.com/ppeMxzJ1l6
— Tom Winter (@Tom_Winter) October 31, 2017