A burning command auto belonging to France's anti-terror "Vigipirate" squad, dubbed "Operation Sentinelle", is pictured during a demonstration as yellow vests protesters keep pressure on French President Emmanuel Macron's government, for the 13th straight weekend of demonstrations, in Paris, France, on February 9, 2019.
The protest in the French capital has passed the National Assembly and will end up near the Eiffel Tower.
There was also an overnight arson attack on the Brittany residence of the National Assembly head - though no immediate link was made to the actions against President Emmanuel Macron.
Police used batons and fired tear gas in Paris to disperse demonstrators, some of whom threw debris at riot police hunkered down.
Police said 31 demonstrators had been arrested Saturday as scuffles broke out between protesters and police.
According to an eyewitness, the person who lost their hand was a photographer attempting to take pictures of people breaking down barriers around the National Assembly building.
"He wanted to bat it away so it didn't explode by his leg - and it went off when he touched it", he added.
Macron's popularity has nosedived since the protests kicked off a year ago in response to a planned fuel tax.
"We put him to one side and called the street medics".
Police confirmed that a protester had a hand injury, but provided no further details other than to say treatment was being provided. This was the 11th time he had marched with the movement, he told AFP.
"The governments of France and Italy have their differences", he said.
But France's Interior Ministry said this week's protest was significantly smaller than last week's.
But a YouGov poll of 1,037 people issued on Thursday suggested that almost two out of three people in France (64 per cent) still support the movement.
In Rome, tens of thousands of people took to the streets to protest the course of Italy's populist government.