Aid organization Doctors Without Borders (MSF) called Friday for migrants to be transferred immediately from overcrowded camps on Greece's Aegean islands to the European mainland.
Following a visit to the islands of Chios and Lesbos, MSF chief Christos Christou told reporters in Athens that the camps resembled the worst humanitarian sites in the world and should be closed down.
The centers were initially built to house a total of 6,200 people, but numbers have ballooned to almost six times that.
He said that "35,000 people live in utter chaos and without any dignity on the Greek islands," adding that on Chios, 300 people were sharing just one toilet.
Misery and squalor
Christou said many residents who had been through torture and abuse, or who were struggling with mental illness, were exposed to degrading camp conditions without getting the right care.
"They receive no help and instead of improving, their condition deteriorates," he said.
Read more: How the EU-Turkey refugee deal works
Greece is a key transit point for migrants hoping to reach the European Union from neighboring Turkey.
The camps on the five islands of Lesbos, Chios, Kos, Samos and Lerisos were set up to process asylum claims under a 2016 deal between the EU and Turkey to curb migrant arrivals.
According to the UN refugee agency, almost 50,000 migrants have reached the Greek islands so far this year.
Greece toughens migration stance
In a bid to restrict numbers further, Greece's conservative government this week announced plans to boost border control and speed up deportations of migrants not eligible for asylum.
Athens wants to shut the overcrowded island camps and replace them with smaller, more restrictive detention centers. Asylum-seekers would be held at the camps until they are either granted refugee status or sent back to Turkey if they are rejected.
In the next few weeks, Greece plans to move up to 20,000 people to the mainland.
MSF chief Christou criticized the measures, saying NGOs would have no access to the new centers, while people detained there would not be able to leave.
They "may become prisons at the end of the day, and will not treat people as humans. They will treat them as problems," he said.
nm/sms (Reuters, dpa)