PARIS, Jan. 5 (Xinhua) -- French President Emmanuel Macron denounced on Saturday via Twitter "extreme violence" from "yellow vest" protests which gathered some 50,000 people across the country.

"Once again, extreme violence came to attack the Republic - its guardians, its representatives, its symbols. Those who commit these acts forget the heart of our civic compact. Justice will be done. Everyone must pill themselves together to bring about debate and dialogue," Macron tweeted.

In Paris, the protest drew about 3,500 demonstrators, much more than the 800 participants last week.

On Saturday afternoon, violence broke out when some demonstrators used construction machinery on 101 Rue de Grenelle in Paris to smash the wooden door of the government building before entering the courtyard.

Government spokesman Benjamin Griveaux and some of his assistants were quickly evacuated through a back door before being placed "in security", reported the French television channel BFMTV.