In the centre of a sweltering, cavernous hall, rows of men sit in silence with nothing to occupy them but the wait.

Signs from an old tourist fair propped up behind them urge visitors to "Explore the Beauty of Nature" with illustrations of coves and beaches in Crete.

But those held in the former Ayia exhibition centre did not come to the Greek island as holidaymakers. They are migrants who risked a journey across the sea from Libya to Europe's southern tip and were then detained and denied the right to apply for asylum.

From Crete, they are now being moved to closed facilities on the mainland.

The right for anyone to request protection, or asylum, is inscribed in EU and international law and in the constitution of Greece itself. But in a move implemented in haste earlier this month and criticised by human rights lawyers, the government has over-ridden that principle for the next three months at least.

The new migration minister, Thanos Plevris, has told the BBC his country faces a "state of emergency". He warns of an "invasion" if Europe does not enact tough measures and talks of the need for strong deterrence.

"Anyone who comes will be detained and returned," he stresses.

Now even people fleeing war in Sudan are locked up with no chance to explain their story.

Inside the old exhibition centre, migrants were warned off speaking to us by the guards. "They're in detention," we were told.

Greece is baking in a heatwave and many of the men were in vests or stripped to the waist. There were a few water taps around the edges but no proper showers and only grubby blankets on the floor. Boxes of donated clothes and toys piled up by the door remained unpacked by guards wary of provoking fights.

Over two days we saw just a couple of hundred migrants at Ayia – from countries including Egypt, Bangladesh and Yemen, we heard, as well as Sudan.

There were 20 or so teenage boys and two women sitting together at the back.

But when 900 people landed from Libya during one weekend earlier this month, the facility was stretched to the limit.

More than 7,000 migrants reached Crete between January and late June, more than three times the number in 2024.

In all, the EU's Frontex border agency recorded almost 20,000 crossings in the Eastern Mediterranean in that period, with the Libya-Crete corridor now the main route.

Traffickers began sending people to Crete in earnest after Italy signed a deeply controversial deal with Libya a couple of years ago that allows for migrants to be intercepted at sea and pushed back despite extensive evidence of human rights abuses.

It was mid-July when the government in Athens made its own move.

"The road to Greece is closing," Prime Minister Kyriakos Mitsotakis told parliament, announcing that all migrants "entering illegally" would be arrested.

A few days later, Mustafa – a 20-year old who ran from the war in Sudan – was detained.