Problems in implementing a controversial EU-Turkey deportation deal have created a bottleneck of some 8,500 migrants on Greek islands, where brawls in overcrowded camps are common.



In the latest outbreak early on Thursday, over a dozen migrants were hurt and tents were torched at Moria camp on Lesvos island in a clash between Afghans and Pakistanis.



As the rival groups went at each other with sticks and stones, hundreds fled the camp for safety, an AFP correspondent said.



Officials say such incidents can only be expected when thousands are crammed in unsuitable facilities, starved of hope and threatened with expulsion.



And adding to the urgency, some of the islands - Lesvos, Chios, Samos and Kos - are gearing for the busy tourist season and locals fear that the migration crisis will undermine bookings. Boris Cheshirkov, spokesman of the UN refugee agency's mission to Lesvos, said his staff had recorded a fight “surge” since the EU-Turkey deal came into effect on March 20, permitting the deportation of migrants whose asylum claims are denied.



“Refugees and migrants are exasperated and worried,” he told AFP.



In addition to fights, some migrants have periodically staged hunger strikes to demand freedom to continue their voyage to Europe.



Making matters worse, asylum checks are proceeding at a snail's pace and a war of words between Brussels and Ankara raises doubts about the agreement's survival.



Ankara has threatened to abandon the deal if its citizens are not granted visa-free travel to most of the bloc. Brussels has conditioned the visa waiver on Ankara narrowing its anti-terror laws -- a step Turkey has adamantly refused to take.



The sheer volume of thousands of asylum requests has overwhelmed authorities, who had initially hoped for a 15-day turnaround per case.



“Nearly everyone has expressed an interest in applying,” says Amnesty International researcher Yiorgos Kosmopoulos, referring to migrants who arrived in Greece from March 20 onwards.



By the end of May, there were some 880 official requests - including 770 by Syrians - and thousands of expressions of interest, according to a government source.



Of these, only two cases have been examined in full, the source said.



However, German-based rights group Pro Asyl says 10 cases have been conclusively examined, a claim Athens has not confirmed.



One of the applicants avoided deportation on the grounds that Turkey would not be a safe destination for him.



But Greek officials have insisted that any such decisions do not create a precedent for others.



“Applications are examined on a case-by-case basis,” the government source said.



”Turkey may be deemed unsafe for one Syrian, but safe for another who has family living there,” the source said.



Athens has also resisted EU pressure to officially declare Turkey a safe country.



The deal is the cornerstone of the EUs plan to curb a crisis that has seen 1.25 million Syrian, Iraqi, Afghan and other migrants enter since 2015.



But out of some 800 experts and translators promised by the European Union, fewer than half were in place by mid-May.



The refugees and migrants are held in special-purpose facilities on Greek islands, where they landed earlier this year after crossing the Aegean from Turkey.



They are detained for a maximum of 25 days. After that point they are allowed to leave the camps but are required to stay on the islands until their asylum applications are processed.



Few migrants have been able to leave Greece after Balkan states began shutting their borders in February to stem an exodus of thousands to northern Europe.



A small number have managed to sneak onto Former Yugoslav Republic of Macedonia but are usually detained and sent back to Greece.



As a result, over 50,000 people have become trapped in Greece, most of them in camps where rights groups have criticised overcrowding, poor sanitation and food quality.



[AFP]