'Drunk' driver arrested after car ploughs through Mardi Gras crowd

Dozens have been injured by a suspected drunk driver who ploughed his vehicle into the crowd at a Mardi Gras parade in New Orleans.

Local police said 21 people were taken to seven different hospitals, including a police officer, in addition to seven others who were treated at the scene.

Five victims are in serious condition.

The truck, traveling along the side of the street open to traffic along the Mid-City parade route, struck three other vehicles, including a dump truck, before veering onto the median where a crowd of people stood watching the procession, according to New Orleans police.

Those hurt were as young as three or four years old, police estimated, however, police said their conditions were stable.

Police Chief Michael Harrison said police did not suspect terrorism and the suspect was being investigated for driving while intoxicated.

The incident happened at the intersection of Orleans and Carrollton Avenue, about 6.45pm local time, according to local media.

A man driving a grey 4WD ute reportedly veered past barriers and into the crowds during the Krewe of Endymion Parade, part of the New Orleans Mardi Gras celebrations.

A witness said the vehicle drove into the crowd after crashing into two other cars.

A man has been handcuffed and arrested at the scene, according to reports.

"At this time it appears it is a subject who was highly intoxicated who struck a number of vehicles and and then veered off hitting a number of innocent people," Chief Harrison said at a press conference.

"[The driver] is now under investigation of DUI and of course hitting a number of people."

DFAT have not confirmed whether any Australians were injured or caught in the crash.