A curfew has been imposed on the Place de la République in central Paris, BFMTV reported. Paris authorities brought in the measure after mass riots broke out around the square. The restriction covers people staying on the plaza during the hours it applies. Officials did not say in the initial reports how long the order would last. République is one of the customary gathering points for demonstrations in the French capital. The move is aimed at stopping the gatherings from tipping over into fresh disorder.