UN Secretary-General António Guterres has condemned Wednesday’s truck attack that killed at least 15 people in the city of New Orleans.

Media reports indicated that a U.S. male citizen had intentionally driven a pick-up truck into a crowd of people celebrating the New Year in the city’s French quarter shortly after 3 a.m. local time.

The 42-year-old suspect was killed in a police shootout that injured two officers.

His potential allegiance to ISIL extremists is under investigation after a flag of the terrorist organisation and improvised explosives were found in the rented vehicle and in other locations nearby, according to the FBI.

“The Secretary-General strongly condemns the attack in New Orleans.

“He condemns the attack, where a driver struck a crowd gathered to celebrate the New Year, reportedly killing at least 15 people and injuring over 30 others,” his Associate Spokesperson, Florencia Soto Nino-Martinez, said on Thursday in New York.

“He extends his condolences to the families and loved ones of those who lost their lives and to the Government and people of Louisiana and the United States.

“He also wishes a swift recovery to those persons injured.”

The U.S. authorities are also investigating possible links between the outrage and a deadly vehicle explosion in Las Vegas on Wednesday morning.

Reports indicated that a Tesla Cybertruck exploded near the entrance of Trump International Hotel on New Year’s Day.

Police said that the driver was killed and seven others were injured when a combination of fireworks, gas tanks and camping fuel was detonated.

In a related development, U.S. President Joe Biden has said that the New Orleans attacker was inspired by Islamic State.

Biden, citing FBI information, told reporters that the attacker “posted videos on social media indicating that he was inspired by ISIS, expressing the desire to kill.”

Biden made his remarks to the press on Wednesday following the car ramming attack in New Orleans early on New Year’s Day that killed at least 15 and wounded dozens.

Biden referred to the Islamic State as ISIS, but it is also called IS, and in the Middle East and many other countries it is known as Daesh.

The outgoing U.S. president stressed that the investigation showed that the perpetrator was a U.S. citizen.

“The FBI has reported to me that the killer was an American citizen, born in Texas,” Biden told reporters.

“He served in the United States army on active duty for many years. He also served in the army reserve until a few years ago,” he added.

Hours after the devastating attack, it remains unclear whether the perpetrator, who was killed after his deadly rampage, had accomplices, U.S. media reported on Wednesday.

Investigators are examining surveillance footage, according to several media outlets, showing a suspicious group of four people.

Initially, it was suspected that they might have placed explosive devices in the affected neighbourhood.