Russian riot police have broken up another demonstration against higher import duties on used foreign cars.The arrest of up to 100 protesters underlines official sensitivity to any gatherings linked to growing economic hardship. At least one cameraman was among those detained. Further protests are due to take place across Russia against punitive tariffs designed to prop up struggling domestic car producers and to discourage Russians from buying second hand vehicles from abroad. They are particularly popular in eastern Russia and especially in the Pacific port city of Vladivostok where the protest was being held. It’s feared many livelihoods there will be threatened by the restrictions. The demonstration was the third in eight days aimed at saving a business which, say organisers, is in imminent danger of collapse.