Tuesday, refugees started setting rubbish cans on fire and throwing stones at police, who in turn responded with tear gas. Reports from inside the centre state that the violence was sparked by authorities striking a minor.A riot broke out at a refugee camp on the Greek island of Lesbos on Tuesday, with police firing tear gas and reports that several refugees and migrants had been injured.Black smoked billowed into the sky after refugees set fire to rubbish bins within the fenced camp near the village of Moria, a few miles from the island’s main port, Mytilini.The trouble started in a wing of the camp where minors are held and then spread, Greek police said. "Riot police are conducting an operation in and out of the camp at the moment," a police spokesman told Reuters..There were reports on social media that refugees had taken control of the camp, chanting “Freedom, freedom” over the public address system.The clashes broke out after a Greek policeman reportedly slapped or hit a minor, refugees inside the camp said.The violence took place during a visit to the camp by Yannis Mouzalas, the Greek migration minister, and a Dutch minister.More than 4,000 refugees and migrants, including women and children, are kept in the camp, which is ringed by razor wire and guarded by Greek police and soldiers.They are among more than 50,000 migrants and refugees who are stranded in Greece after its northern neighbour, Macedonia, closed its border in March, after similar action was taken by other Balkan countries.Frustration has been growing for weeks, with violence breaking out on Aegean islands such as Lesbos and Chios and at Idomeni on the the Greek border with Macedonia, where Macedonian police have fired rubber bullets and stun grenades at refugees trying to scale the frontier fence..Multiple vote option enabled for following poll: