A "yellow vest" anti-government protester has died after being hit by a truck in southern France, a local prosecutor said Thursday.

The incident happened during the night at a roundabout near a motorway exit in the city of Avignon.

"The driver of the truck has been taken into custody. The victim was 23-years-old," said the deputy prosecutor for Avignon, Caroline Armand, confirming a report on French television news channel LCI.

"It appears the driver is a Polish national," she added.

A statement from the Vaucluse prefect's office said the protester was attended by emergency services but died from his wounds overnight.

The "yellow vest" protesters, so-called because of the high-visibility jackets they wear, first took to the streets on November 17 to protest fuel tax hikes.

The protests have ballooned into a mass movement over rising living costs, and have spiraled into weekends of violence and vandalism in Paris and other cities.

The latest death was the sixth during the nationwide road blockades and protests, all of which appear to have been accidents. More than 1,400 were also injured in the protests.

On November 17, a demonstrator was killed in the eastern Savoie region after she was hit by a motorist.

Two days later, a motorcyclist was struck by a van which was trying to avoid protesters, and died of his injuries the next day.

On the night of December 1-2, a motorist was killed after colliding with a truck that had stopped in traffic that had built up due to a "yellow vest" blockade in Arles, southern France.

Also on December 1 an 80-year-old woman was injured by a tear-gas grenade in Marseille, and died the next day.

Meanwhile, the French government on Thursday urged "yellow vest" protesters not to hold another round of demonstrations this weekend as police hunted for a second day for the fugitive gunman who attacked a Christmas market in the eastern city of Strasbourg.

Government spokesman Benjamin Griveaux called on the anti-government protesters to be "reasonable", citing the strain on security forces after the bloodshed in Strasbourg on Tuesday evening.

Police across several European countries have joined a manhunt for the main suspect, a 29-year-old Strasbourg native, who killed three and injured 13, according to an updated toll from French authorities.

The suspected killer, identified as Cherif Chekatt, is said to have been injured after exchanging fire with soldiers, but managed to escape and has not been seen since.

"Our security forces have been deployed extensively these past few weeks," Griveaux told CNews television.

"It would be better if everyone could go about their business calmly on Saturday, before the year-end celebrations with their families, instead of demonstrating and putting our security forces to work once again," he added.

So-called "yellow vest" protesters, known for their fluorescent high-visibility jackets, had called for a fifth round of protests this Saturday against President Emmanuel Macron.