(Credit: AP)

The Associated Press is reporting that investigators are working to determine what led a pickup truck driver to plow down people on a riverfront bike path near the World Trade Center, killing eight.

New York's mayor called Tuesday's attack "a particularly cowardly act of terror."

The driver, who is said to be an Uber driver, is in critical condition after police shot him in the abdomen.

Authorities said after crashing the truck, he brandished air guns and yelled what witnesses said was "Allahu Akbar," which is Arabic for "God is great."

Officials who weren't authorized to discuss the investigation and spoke to The Associated Press on the condition of anonymity identified the attacker as 29-year-old Sayfullo Saipov. They say he came to the U.S. legally from Uzbekistan in 2010.

One of the dead is from Belgium and five others were from Argentina.

New York City is reportedly increasing security in public areas, transportation hubs and airports.