On April 20, more than 160 asylum seekers and migrants reached Lesbos and Chios from Turkey. The police detained them in the closed facilities on those islands, Moria and VIAL, as they do everyone who has arrived on the islands since the ill-conceived EU-Turkey deal came into force a month ago.

But this blanket and automatic detention is unjustifiable on legal, humanitarian and practical grounds.

First, authorities should not automatically detain asylum seekers more than the shortest reasonable time. When they do, and alternatives exist, it constitutes arbitrary detention under international law.

Second, the conditions in Moria and VIAL, where about 4,500 people are held, are unacceptably poor. When the facilities became prison-like detention centers, the UN refugee agency, UNHCR, and most nongovernmental organizations stopped providing services.

Human Rights Watch research this month found that many of the detainees are especially vulnerable--unaccompanied children, single mothers, pregnant women, and people with disabilities. We saw people in wheelchairs and people under severe psychological stress.

Women said they are afraid to shower alone and some people have developed rashes. During our research in VIAL, people told us that there is no hot water and that they get cold water only at certain times. The Hellenic Red Cross and army provide health care but only basic services and at limited times.

“It is so difficult here,” said a 25-year-old single mother from Afghanistan detained in VIAL with her 5-year-old son. “You are inside a prison. The food is not edible, and every day, half of the day, there is no running water.”

The answer to these problems is clear.  Before the EU-Turkey deal, Moria and VIAL were open reception and registration camps, as were the other so-called Hotspots on Samos, Leros and Kos. All of them can become open facilities once again.

Making these camps open facilities would relieve the overcrowding and let UNHCR and nongovernmental organizations return to provide services. It would also restore the migrants’ and asylum seekers’ freedom of movement. The risk that people would leave for the mainland is minimal without proper documentation to board a ferry.

On April 21, guards at VIAL opened the gates to release those who had been detained for the legal limit of 25 days. But the other detainees protested loudly and the police let them out. The police made the right choice by removing the locks. Now the government should make it final by returning these facilities to open camps.