Migrant crisis: Desperation on the Greek border
At the migrant camp at Idomeni, on the border between Greece and Macedonia, there is desperation in the air.
"I am begging Macedonia to let us in," said a young Syrian man as he queued at the border gate. He had been standing in the rain for hours.
The wire-mesh gate that every migrant and refugee has to pass through has been closed on the Macedonian side for much of the last 24 hours. Authorities at the camp said this was because the next national frontier on the trail, the Macedonia-Serbia border, had been closed.
Macedonia will not let anyone across its southern border until the one in the north reopens. It's a classic domino effect.
Moving in the wrong direction
The process of moving Syrians, Iraqis and Afghans through Greece has been a well-oiled machine. Buses have been leaving around the clock from Athens to take them to the border with Macedonia.
But the system is now creaking at the edges. There was trouble at the crossing on Tuesday as a new policy blocking Afghan nationals from proceeding led to dozens of Afghans cutting through the border fence and storming into Macedonia.
Riot police were deployed and calm was eventually restored. Reports suggest Afghans were then bussed south as far as Athens. Moving on the migrant trail, but in the wrong direction.
At the camp on Wednesday, aid workers said some Afghans had fled into the surrounding countryside rather than get on one of the buses. They plan to hide out in the hope that restrictions will be lifted.
And the banning of Afghans from proceeding northwards has made Iraqis and Syrians nervous. Will they be the next nationality to be stopped?
Gemma Gillie is a softly spoken Scot from the Borders. She is based at the camp as a spokeswoman for Medecins Sans Frontieres and says all migrants at the camp are worried about progressing.
"The restrictions for Afghans were applied so abruptly, there's a real feeling among Syrians and Iraqis that any point it could be them as well," she says.
"And the new restrictions have also meant that Iraqis and Syrians, in addition to registration paperwork, now need to have an ID document. Many of these people literally fled with the clothes on their back, so many don't have that and are anxious that they won't be able to cross."
She also fears that Greece lacks the capacity to cope with the number of stranded people, and that thousands of people will be left without adequate shelter, clean water or food.
So what is being done by those in charge? Austria chaired a meeting of ministers from western Balkan states on Wednesday, much to the annoyance of Greece, which wasn't invited.
They agreed that the influx of migrants and refugees had to be "substantially reduced" and that anyone "not in need of international protection" would be turned away.
The underlying concern now is that border gates through the Balkans will start slamming shut, creating a new humanitarian crisis in Greece.