The mounted officers advanced behind serried ranks of police on foot holding up their shields like Roman legionaries. In front of them, on the fashionable Rue de Bretagne in central Paris, were the “yellow-vest” protesters and masked, black-clad youths, sending shoppers and patrons of pavement ­cafés scurrying indoors for cover.

“No one was expecting trouble in this area,” Françoise Perrin, 43, an ­observer, told The Sunday Telegraph.

Ms Perrin, one of dozens of terrified Parisians and tourists in the historic Marais district caught between a mob of protesters and riot police on horseback, added: “We were just about to order a drink, then we looked up and saw what looked like a military formation heading towards us. Then we looked the other way, and saw the protesters. We got the fright of our lives.”

The police managed to prevent the mob from looting shops, smashing windows or attacking parked cars, pursuing them through the narrow medieval streets of one of Paris’s oldest and most picturesque quarters.