At least 15 dead as vehicle crashes into New Orleans crowd

About 400 officers were deployed to protect the area. (Photo/AFP)

The death toll in a pickup truck attack in New Orleans, Louisiana, has risen to 15, New Orleans Coroner Dr Dwight McKenna said.

"As of now, 15 people are deceased. It will take several days to perform all autopsies. Once we complete the autopsies and talk with the next of kin, we will release the identifications of the victims," McKenna said in a statement on Wednesday.

Earlier, 35 other people were also reported injured when the truck ploughed through the heart of the French Quarter around 3.15 am (0915GMT) on Wednesday.

The area is popular with tourists and is a hotspot for celebrations around major holidays, especially New Year's Eve.

Police said the attacker drove the truck onto a sidewalk and around a police car that was parked to block traffic from entering the area to carry out the attack.

About 400 officers were deployed to protect the area.

Range of suspects

The FBI has said it does not believe the man who rammed the pickup truck into the New Year's partygoers, who has been identified as Shamsud-Din Jabbar, a 42-year-old US citizen and Army veteran, acted alone.

"We do not believe that Jabbar was solely responsible. We are aggressively running down every lead, including those of his known associates," Alethea Duncan, the FBI assistant special agent in charge of the New Orleans field office, told reporters at a press briefing.

"We cannot go into details about the subject's history. What I can tell you is the person was an Army veteran. We believe he was honourably discharged, but we're working through this process, figuring out all this information," Duncan added.

Jabbar, from Texas, was previously identified by the bureau as a suspect in the terror attack.

Asked how many accomplices authorities believe Jabbar had, Duncan said, "It's a range of suspects."

According to sources cited by ABC News, New Orleans police have reviewed surveillance footage that appears to show several individuals planting potential explosive devices prior to the vehicle attack.

Authorities are working to identify the individuals seen on camera and bring them into custody. Meanwhile, steel barricades were not up on Bourbon Street at the time of the incident.

State of emergency

Louisiana Governor Jeff Landry declared a state of emergency to facilitate cooperation between federal, state and local agencies "to bring all of the resources necessary to get this city safe."

He further mobilised a military police company to assist law enforcement.

"It is important for our citizens and guests of the state to know that we're doing everything we can to secure their safety in this city. We want to make it clear: the Superdome and the surrounding area are safe," he said.

The Sugar Bowl, an American college football championship game that was to be played at the Superdome on New Year's Day, has been delayed until Thursday.

Multiple weapons, a Daesh flag and a potential improvised explosive device were found inside the truck, according to the FBI.

According to Texas records, Jabbar was charged with a misdemeanour in 2002 for property theft and arrested in 2005 for driving with an invalid license.