U.S. President Donald Trump has signaled a major crackdown on immigration after police detained an Uzbek man suspected of mowing down dozens of people on a New York City bicycle path, killing eight and injuring several others.
Calling the attacker a "terrorist," Trump on November 1 said he would work with Congress to “immediately” terminate a Green Card visa program under which the suspect legally entered the United States in 2010.
He also ordered more "extreme vetting" of immigrants, requiring deeper information during the screening process with U.S. officials, such as details on the person’s travels for the previous decade.
Trump said that "we will take all necessary steps to protect our people" from "these animals."
The moves come after police identified a 29-year-old Uzbek national named Sayfullo Saipov as the man who drove a rented pickup truck into people on a New York City bicycle path on October 31.
U.S. prosecutors formally charged Saipov with causing the deaths of eight people and of providing material support and resources to the extremist group Islamic State (IS). Other charges are likely to follow.
Meanwhile, the Federal Bureau of Investigation said it was seeking information on Mukhammadzoir Kadirov, a 32-year-old Uzbek native who also has immigrated to the United States. The FBI did not specify why the second man was being sought.
The deadly incident, described by Trump and other officials as a "terrorist attack," followed a series of attacks in major European cities in which suspected Islamist militants have mowed people down with cars or trucks.
It took place in Lower Manhattan, close to the spot where the Twin Towers of the World Trade Center stood before Al-Qaeda terrorists brought them down with hijacked jets in the September 11, 2011, terror attacks.
Police sources in New York identified the suspect as a 29-year-old Uzbek national named Sayfullo Saipov, who came to the United States legally in 2010.
A source in Uzbekistan's security services told RFE/RL's Uzbek Service that Saipov's mother, father, and 17-year-old sister were being questioned in the Central Asian country on November 1. The source was not authorized to speak publicly about the matter and spoke on condition of anonymity.
That investigation was launched after Uzbek President Shavkat Mirziyoev said in a statement posted to the Foreign Ministry's website on November 1 that his government "is ready to use all forces and resources to help in the investigation of this act of terror."
New York police said the suspect, whom they shot and detained at the scene, used a rented pickup truck to drive into pedestrians and cyclists on a bike path close to the Hudson River in a busy part of Manhattan.
Eyewitnesses said the suspect shouted out "Allahu Akbar" or "God is greatest" after crashing the truck into pedestrians and a school bus.
New York State Governor Andrew Cuomo said that Saipov is the only suspect in what appeared to be a "lone wolf" attack.
Cuomo told CNN that Saipov was "associated with ISIS, and he was radicalized domestically" in the United States. ISIS is a common acronym used for the extremist group Islamic State (IS).
"After he came to the United States is when he started to become informed about ISIS and radical Islamic tactics," Cuomo said. "We have no evidence yet of associations or a continuing plot or associated plots, and our only evidence to date is that this was an isolated incident that he himself performed."
The governor also confirmed earlier U.S. media reports that "a note" referring to IS militants was found at the scene. U.S. media reports said the note was written in Arabic and pledged allegiance to IS.
New York City Mayor Bill de Blasio said the incident was "an act of terror, and a particularly cowardly act of terror, aimed at innocent civilians, aimed at people going about their lives who had no idea what was about to hit them."
WATCH: A bystander caught the arrest on camera of the man suspected of using a vehicle to run down people on a bicycle path in New York City, killing at least eight.
An Uzbek immigrant in the United States who said he knows Saipov, Mirrakhmat Muminov, told RFE/RL that Saipov lived near the city of Stow, Ohio from 2011 to 2013 before moving to Florida in 2013.
Muminov said Saipov worked for many years as a truck driver.
He said Saipov has a wife and two children and is a native of Tashkent. He described the suspect as somewhat "aggressive" but said he was not very religious before he went to Florida.
Muminov said he thinks Saipov became more radical because he was getting information from Islamic extremists through the Internet.
Still, Muminov said no one thought Saipov was capable of committing a terrorist attack.
He said he is "shocked" by news reports about the attack and can't imagine what kind "of monsters were in his head."
Uber said in a statement that Saipov had worked as a driver for the ride service before the attack. The company said it was "horrified by this senseless act of violence" and has banned Saipov from the Uber app.
Saipov had been reportedly arrested in Missouri last year over a traffic fine.
Authorities said five Argentinians and one Belgian were among the eight people killed in the attack.
At least 11 people were hospitalized with injuries described as serious but not life-threatening, according to emergency services.
Police said the suspect used a truck rented from a New Jersey Home Depot hardware store in his rampage, and after crashing the vehicle, he emerged wielding what they said were fake guns.
Video posted by NBCNewYork.com showed Saipov after crashing the truck running through traffic with what appeared to be a BB gun and paintball gun.
Authorities said police took Saipov into custody and transported him to New York's Bellevue Hospital for treatment of an injury to the abdomen that was not deemed to be life-threatening.
Cuomo ordered increased security at New York's airports, bridges, tunnels, and mass transit systems, and directed that the lights on the spire of One World Trade Center be lit in red, white, and blue in honor of "freedom and democracy."
But Cuomo said there was no information about a credible threat of further attacks, saying the heightened security measures were precautionary.
De Blasio said the New York City Marathon would go ahead as scheduled on November 5 and that the thousands of runners who take part would be "well protected."
WATCH: Mobile phone footage shows the first moments after a New York school bus was hit by an Uzbek driver. Two staff and two children were injured on the bus. (AP)
Similar To Attacks In Europe
Similar attacks by Islamic extremists using vehicles to crash into pedestrians have killed dozens of people in Europe during the last 16 months.
A Somali-born student at Ohio State University -- described by authorities as an Islamic extremist inspired by IS -- also carried out a vehicle attack in Ohio in November 2016 but did not kill anyone.
In July 2016, a man drove a large truck into a crowd celebrating Bastille Day in the French city of Nice, killing 86 people and injuring hundreds more. The IS group claimed responsibility for the attack.
Five months later, a Tunisian asylum seeker who had pledged allegiance to IS plowed a truck into a crowded Christmas market in central Berlin, killing 12 people and injuring 48.
In April of this year, a failed asylum seeker from Uzbekistan careened down a busy street in a truck in central Stockholm, crashing into a department store and killing three people in what the prime minister called a terrorist attack.
And on August 17, a driver rammed his van into crowds in the heart of Barcelona, killing 13 people, in an attack authorities said was carried out by suspected Islamist militants.
Uzbek security officials, speaking on condition of anonymity because they were not authorized to talk to the media, told RFE/RL that Saipov's parents live in Tashkent's Uchtepa district and are merchants at the city's Bektopi market.
The officials in Uzbekistan, where the state's concern about Islamic extremism have increased as citizens of the predominantly Muslim former Soviet republic have traveled to Afghanistan and the Middle East to fight alongside Islamic extremists, said the family was not known to be particularly religious.
Referring to the suspect as a "terrorist," Trump said he had come to the United States under a program widely known as the Green Card lottery, in which a limited number of visas are granted to people from countries with low rates of U.S. immigration.
In remarks on Twitter, Trump criticized the Diversity Visa Immigrant Program and said the allotment of visas should be "merit based."
With reporting by RFE/RL's Uzbek Service, RFE/RL correspondent Pete Baumgartner, AFP, AP, Reuters, dpa, NBCNewYork.com, and ABC News