The attack happened at around 3.15am local time on Wednesday along Bourbon Street, known worldwide as one of the largest destinations for New Year's Eve parties.

Crowds in the city were also ballooning ahead of the Sugar Bowl college football play-off game at the nearby Superdome later in the day.

Later, law enforcement officials told the Associated Press that the suspect had been killed in a firefight with police.

placeholder image — Emergency personnel work the scene on Bourbon Street after a vehicle drove into a crowd on New Orleans' Canal and Bourbon Street, Wednesday Jan. 1, 2025. (AP Photo/Gerald Herbert)

At a news conference, New Orleans Mayor LaToya Cantrell described the incident as a "terrorist attack" and the city's police chief said the act was clearly intentional.

But an assistant FBI agent in charge declared it was "not a terrorist event".

The news conference ended before authorities could reconcile the two statements.

Alethea Duncan , an assistant special agent in charge of the FBI's New Orleans field office, said officials are investigating the discovery of at least one suspected improvised explosive device at the scene.

Police Commissioner Anne Kirkpatrick said of the attacker: "He was hell-bent on creating the carnage and the damage that he did.

"It was very intentional behaviour. This man was trying to run over as many people as he could."

Two police officers who were shot after the driver emerged from the truck are in a stable condition, she added.

She said officers would work to ensure safety at the Sugar Bowl, indicating that the game would go ahead as scheduled.

Officials did not immediately provide an update on the status of the driver, whether there was an ongoing threat to the public, or offer a suspected motive for the incident.

New Orleans' emergency preparedness department, Nola Ready , said the casualties had been taken to five local hospitals.

President Joe Biden said the FBI is investigating the "horrific incident" as "an act of terrorism" and that he has directed his team to ensure every resource is available as authorities work to "get to the bottom of what happened as quickly as possible".

"My heart goes out to the victims and their families who were simply trying to celebrate the holiday," Mr Biden said in a written statement.

"There is no justification for violence of any kind, and we will not tolerate any attack on any of our nation's communities."

Attorney General Merrick Garland has also been informed, the Justice Department said.