Swiss police surrounded a group of several hundred violent protesters following clashes that marred a largely peaceful demonstration against the upcoming Group of Seven summit in France.
Authorities were checking the identities of those contained and some could face arrest and prosecution, Laurent Paoliello, a spokesman for local authorities, told Swiss broadcaster RTS on Sunday.
Paoliello said property damage was limited and praised the police operation. No injuries were reported.
Thousands of demonstrators have gathered in Geneva to protest against the G7 summit, which is due to begin on Monday in the French lakeside town of Évian, 50km across the border from Switzerland.
The peaceful march was overshadowed by a hard core of masked protesters who tore up paving stones and smashed several shop windows. Police responded with tear gas and later deployed water cannon to disperse the unrest.
