A man in a rented pickup truck has mowed down pedestrians and cyclists along a busy bike path near the World Trade Center memorial, killing at least eight and seriously injuring at least 11 in what New York Mayor Bill de Blasio called “a particularly cowardly act of terror.”

The driver was shot in the abdomen by police after jumping out of the truck with what turned out to be a fake gun in each hand and shouting what witnesses said was “Allahu Akbar,” Arabic for “God is great,” authorities said. The man underwent surgery and was in critical condition but was expected to survive.

Officials identified the attacker as 29-year-old Sayfullo Saipov to various US media and said he is from Uzbekistan and came to the US legally in 2010. The officials said Saipov has a Florida driver's license and may have been staying in New Jersey, and a family friend described roots he had in Ohio.

The driver in the attack barrelled along the bike path in a rented Home Depot truck for the equivalent of about 14 blocks, or around eight-tenths of a mile, before slamming into a small yellow school bus. The mayhem and the burst of police gunfire set off panic in the neighborhood and left the pavement strewn with mangled bicycles and bodies that were soon covered with sheets.

New York Governor Andrew Cuomo called it a “lone wolf” attack and said there was no evidence to suggest it was part of a wider plot.

The city's police commissioner, James O'Neill, said a statement the driver made as he got out of the truck and the method of attack led police to conclude it was a terrorist act.

On Twitter, President Donald Trump called it “another attack by a very sick and deranged person” and declared, “NOT IN THE U.S.A.!”

While police did not specifically blame Isis for the New York bloodshed, Mr Trump railed against the extremist group, tweeting, “We must not allow ISIS to return, or enter, our country after defeating them in the Middle East and elsewhere. Enough!”