A driver behind the wheel of a pickup truck rammed into a crowd of New Orleans revelers on Bourbon Street early on New Year’s Day, killing at least 15 people in what the FBI is investigating as an act of terrorism.

The terror attack in New Orleans was one of the deadliest on US soil since 9/11 after the death toll rose to 15 on Wednesday afternoon.

The death toll in the suspected terrorist attack in New Orleans involving a car ramming has risen to 15, several US media outlets reported, citing a statement from the city's coroner, Dwight McKenna.