NEW YORK — A suspected terrorist in a rented pickup plowed through a busy bicycle path near the World Trade Center memorial in Lower Manhattan on Tuesday and fatally struck eight people, then emerged screaming in Arabic and pointing imitation guns before he was shot by police.

The stunning Halloween attack, just hours before the city's parade and festivities were to kick off, was confirmed as a terror incident by authorities at a late-afternoon news briefing. New York City Mayor Bill de Blasio and Gov. Andrew Cuomo urged New Yorkers to be vigilant — but not afraid.

"This was an act of terror and a cowardly act of terror," de Blasio said, noting that New York City won't react with fear. “We will respond as we always do, we will be undeterred.”

The afternoon incident began with a driver careening on to a pedestrian walkway and bike path, running over pedestrians and bikers, the New York police said via Twitter. Witnesses described a horrific scene with people diving from the path of the speeding truck.

Law enforcement officials identified the driver as Sayfullo Saipov, 29, the Associated Press and Fox News reported. Witnesses told police the attacker yelled, “Allahu Akbar!” — “God is great” in Arabic — as he got out of the truck, AP reported, citing an official who was not authorized to discuss the case publicly and spoke on condition of anonymity.

Asked about that at a news conference, New York City Police Commissioner James O’Neill replied: “Yeah. He did make a statement when he exited the vehicle.” He said the statement and the method of attack led police to conclude it was a terrorist act.

Saipov was shot in the abdomen by police. He is expected to survive.

A U.S. official familiar with the investigation said Saipov is from Uzbekistan and came to the U.S. in 2010. The official was briefed on the investigation but was not authorized to speak publicly and spoke to The Associated Press on condition of anonymity. Saipov rented the van Tuesday afternoon at about 2 p.m., about an hour before the attack.

The attack seemed haphazard on some level but is similar to terror attacks around the world in which terrorists use simple methods — such as a speeding truck into a crowd — to inflict casualties.

"There are several fatalities and numerous people injured," police tweeted shortly after the carnage began. "The vehicle continued south, striking another vehicle. The suspect exited the vehicle displaying imitation firearms and was shot by NYPD."

Police said the "imitation firearms" were a pellet gun and a paintball gun.

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In addition to the eight killed, 11 people were injured, police said. Cuomo called the suspect, who is being treated at an undisclosed hospital, a "lone wolf" attacker with terrorist intentions. There's no indication of a wider plot or that Saipov was part of a terror cell planning other operations, Cuomo said.

The governor urged the city to enjoy Halloween and not succomb to fear.

“To New Yorkers, be New Yorkers. Live your life," Cuomo said.

Joseph Pentangelo, a spokesman for the Port Authority of New York & New Jersey Police Department, said counterterrorism units — officers with heavy artillery and tactical gear — were deployed to airports, bridges and tunnels. He said the officers also were dispatched to sweep PATH stations.

Pentangelo said there were no lockdowns at the area's three major airports. He said the Holland and Lincoln tunnels were open, but that traffic was backed up more than usual.

"It's rush hour, and there was traffic anticipated tonight anyway," Pentangelo said, alluding to the Village Halloween Parade, which was expected to attract thousands before the incident. The 7 p.m. parade proceeded with a heavy dose of security.

The parade saw heavy police presence – on sidewalks, at intersections, among the crowd. But despite the day’s tragic headlines, it appeared to be a typical New York Halloween night parade, with droves of costumed kids clamoring for candy and watching floats.

“I’m not going to let it scare me,” Cathryn Strobl, a 23-year-old New Yorker, said as she waited for the parade to start in her Buffy the Vampire Slayer costume. “You can’t let it stop you from living your life.”

President Trump was briefed on the incident, and tweeted, "In NYC, looks like another attack by a very sick and deranged person. Law enforcement is following this closely. NOT IN THE U.S.A.!"

Also briefed was Acting Secretary of Homeland Security Elaine Duke, the department said in a statement Tuesday evening.

"The Department is closely monitoring the situation and working with our federal, state and local partners in responding to and investigating this tragedy," the statement said. "We have recently seen attacks like this one throughout the world. DHS and its law enforcement partners remain vigilant and committed to safeguarding the American people."

Adding to concern is the upcoming New York Marathon, scheduled for Sunday. The New York Road Runners group said it is looking at security around the race route.

"We are monitoring the situation closely with our city, state, and federal agency partners, particularly the NYPD," the group said in a statement. "For this weekend’s marathon, as with all of our events, the safety and security of our runners, staff, volunteers, and spectators is our top priority. Together with our agency partners, we have extensive safety and security measures in place, both visible and behind the scenes. We are constantly reviewing our plans with law enforcement and will consider any necessary modifications or enhancements."

Photos from the scene show a Home Depot pickup with heavy front-end damage.

An Associated Press photographer witnessed at least two bodies lying motionless on the path beneath tarps.

Szymon Cholostiakow, 29, a Polish tourist visiting New York City for the first time, said he was shocked by the attack.

"It 's very weird that something like this is happening in one of the biggest cities in the world," he said while watching emergency vehicles near the scene. "I hope people are OK."

New York resident Ashley Bacon, 29, was two blocks away when chaos broke out.

“We heard the screaming,” she said. “I’ve never seen so many emergency vehicles.”

Nico Field, 27, was at his job as a day care worker in the Goldman Sachs building near the attack scene shortly after 3 p.m. when he heard noises.

"I heard a few quick pops, pop, pop, pop, pop," Field said. "I could have sworn it was gunshots. I know what gunshots sound like. But I said it can’t be gunshots, it must be a tire or a train.”

Soon afterward, a coworker told him emergency workers had confirmed the horrific attack.

"It's surreal, pretty bizarre," he said.

Contributing: John Bacon and Eli Blumenthal, USA TODAY; the Associated Press