According to the RaiNews 24 broadcaster, the detainees allegedly planned to partake in demonstration of the international No Border group which will protest against restraints on free movement of migrants in Europe later in the day in Ventimiglia.
Ventimiglia which currently hosts a Red Cross camp for up to 500 migrants was gripped by unrest earlier in the week.
After several dozens of No Border activists arrived in the camp, some 140 migrants tried to escape illegally to France on Friday, but were detained by French law enforcement troops and sent back to Italy.
On Saturday night, No Border activists clashed with police in Ventimiglia, two people were arrested.
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