Lesbos, Greece: Greece was due on Monday to send the first migrants back to Turkey under a hugely controversial EU deal that has faced heavy criticism from rights groups.
Turkish Interior Minister Efkan Ala has said his country is ready to receive 500 people Monday and that Greek authorities had provided 400 names, although these numbers could change.
The action will be focused on Lesbos, a Greek holiday island that has served as the European gateway for hundreds of thousands of refugees and migrants arriving in flimsy boats from Turkey in the last year.
Police sources on Lesbos on Sunday said there had been a flurry of last-minute asylum applications amongst the 3,300 migrants there.
"We... have over two thousand people that have stated their wish to seek asylum and we need to see a credible process go ahead with the Greek asylum service for those that wish to express their protection concerns," said Boris Cheshirkov, the UN refugee agency spokesman on Lesbos.
Migrants could also be sent back from other islands that have seen large influxes, such as Chios, where members of EU border agency Frontex were seen arriving Sunday.
Greek officials have been tight-lipped over who and how many migrants will cross the Aegean Sea back to Turkey.
But state news agency ANA reported that some 250 migrants from Bangladesh, Pakistan, Sri Lanka and African nations would be sent back daily between Monday and Wednesday.
Yiorgos Kyritsis, spokesman for Greece's refugee coordination unit, insisted Monday's operation only "involves people who have not requested asylum".
The European Union signed the controversial deal with Turkey in March as it wrestles with the continent's worst migration crisis since World War II, with more than a million people arriving from the Middle East and elsewhere last year.
Under the agreement, designed to halt the influx from Turkey, all "irregular migrants" arriving since March 20 face being sent back, although the deal calls for each case to be examined individually.
For every Syrian refugee returned, another Syrian refugee will be resettled from Turkey to the EU, with numbers capped at 72,000.
Rights concerns
Rights groups have criticised the deal, questioning whether it is legal and ethical.
"We don't know what is going to actually happen," senior UN migration official Peter Sutherland said this weekend.
"But if there is any question of collective deportations without individuals being given the right to claim asylum that is illegal."
Many migrants on the islands have complained of not being given sufficient time and access to the asylum procedure.
Anas al-Bakhr, a Syrian engineer from Homs who is among those stuck on Chios island, said police marked his arrival date as March 20 when the deal entered force even though he arrived the day before.
"They said the computers were broken that day," Bakhr said.
Vassilis Balas, manager of the Suda refugee camp in Chios said many migrants have only just started applying for asylum.
"UNHCR (the UN refugee agency) is facilitating this process in the camps. It's facilitating a process that actually should have been done by the police and other authorities in the hotspot," he said.
