Shocking images and footage posted online show the Yellow Vest protestor bleeding profusely from where their hand used to be.
PARIS-Thousands of French "yellow vest" demonstrators marched February 9 for their 13th weekend of action, which included scuffles in Paris and a demonstrator's hand mangled by a small explosive.
The police responded with tear gas and anti-riot munitions.
The movement of the "yellow jackets" holds protest rally for the 13th time, as usual, at the end of the week.
In a graphic video of the aftermath, French paramedics are seen gathered around the injured protester at the National Assembly gates, providing emergency medical treatment and preventing onlookers from getting too close.
The man, 30, was treated in hospital after a French police grenade exploded as he tried to bat it away with his hand while rioters attempted to storm the national assembly in Paris. France's interior Christophe Castaner tweeted his indignation over the auto being set on fire saying,"These attacks are intolerable".
A vehicle, motorbikes and multiple trash bins were set ablaze as the protest moved toward the city's Invalides monument but France's Interior Ministry said this week's protest was significantly smaller than last week's.
Representatives for the yellow vests disputed the previous week's numbers, claiming the turnout was higher.
Thousands of protesters turned out Saturday in the French Mediterranean ports of Marseille and Montpellier and also in Bordeaux and Toulouse in the southwest - strongholds of the movements - as well as several cities in the north and west of France.
Although, the eurozone's second largest economy's president, Emmanuel Macron had promised an exhaustive mining of new jobs during taking the office in 2017, Macron's attempts appeared to be pulled back since last Autumn upon exposure to violent protests, which initially introduced as a "Yellow Vest" protest to deduce taxes on energies such as oil.
In December, Mr Macron said he was "partly responsible" for an "insufficient response" to the protests that have rocked the country every Saturday.