ATHENS, Greece — The U.N. refugee agency pulled out staff Tuesday from facilities on Lesbos and other Greek islands being used to detain refugees and migrants as an international deal with Turkey came under further strain.
Greece began arresting everyone arriving in boats from Turkey after the agreement went into effect Sunday. They are being held at European Union-supervised registration centers known as "hotspots" in what Greek government officials describe as "compulsory supervision."
Under the deal, detained migrants and refugees will be sent back to Turkey, which in return will receive additional EU financial aid and join an EU resettlement program for Syrians and others fleeing war.
"The UNHCR is concerned that the EU-Turkey deal is being implemented before the required safeguards are in place in Greece," agency spokeswoman Melissa Fleming said in Geneva.
"Greece does not have sufficient capacity on the islands for assessing asylum claims, nor the proper conditions to accommodate people decently and safely pending an examination of their cases."
About 2,000 people have been detained since the deal took effect, with migrants still arriving in boats despite the crackdown.
"Clearly we do not believe that, so far, Turkey has implemented what has been agreed. Migration flows are not significantly lower ... that should have happened immediately," government spokeswoman Olga Gerovasili said.
Greek Prime Minister Alexis Tsipras, she said, telephoned German Chancellor Angela Merkel Tuesday and urged her to press Turkey to crack down on migrant smugglers.
She said full implementation of the agreement would require preparations for about 10 days.
More than 50,000 refugees and migrants are currently stranded in Greece, with many still camped out at the closed Greek-Macedonia border where protests continued for a third day.
One protester, a young Syrian man, set himself on fire during the protest. He was hospitalized with burns to his upper body, doctors said.
About 12,000 refugees and migrants remain outside the border village of Idomeni, despite an appeal by the Greek government to move to nearby army-built shelters.
Greek state TV began running short bulletins in Arabic for refugees, urging them to leave the border camp.
Jamey Keaten reported from Geneva. Costas Kantouris in Thessaloniki contributed to this report.