Six people were reported killed when a man drove a pickup truck down a lengthy stretch of a bike path next to the Hudson River in Lower Manhattan on Tuesday afternoon before he jumped out with two fake guns and was shot by police officers, the authorities said.

The attacker, in a Home Depot truck, hit numerous people as he drove south on the bike path, officials said. At least 11 people were reported injured.

The driver was being treated at a nearby hospital. He also crashed into a school bus as he careened down as many as 20 city blocks near Stuyvesant High School, a senior law enforcement official said. It was unclear if anyone was on the bus.

A large section of the West Side Highway was closed for the investigation as hundreds of officers, including the bomb squad, responded to the scene. The truck came to a rest near Chambers and West Streets.
The police said they were not looking for additional suspects.
Students at Stuyvesant High School reported that they saw a man shooting from a pickup truck, and then saw the truck turn and strike a school bus.

Ramon Cruz, 27, said he saw a man crash his white pickup truck and emerge from the vehicle at Chambers and West Streets as school was letting out.

Mr. Cruz said the front of the truck was smashed and the driver appeared injured. Then Mr. Cruz said he heard someone yell, “He’s got a gun, run, run!”

Several nearby buildings, including Stuyvesant, were placed on lockdown.