A law enforcement official says at least six people were killed and nine injured when a rented van drove on a bike path near the World Trade Center in New York City.
The official was familiar with the investigation but wasn't authorized to speak publicly and spoke on condition of anonymity.
The official says it is being investigated as a possible case of terrorism.
A motorist drove onto a busy bicycle path near the World Trade Center memorial and struck several people, then emerged from the vehicle screaming and firing what appeared to be a gun, police and witnesses said.
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!''
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 plow into people on a popular bike path adjacent to the West Side Highway. 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,'' Yi 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.