IDOMENI, Greece — Relief agencies have set up a tent city at Greece’s border with Macedonia to cope with the growing number of migrants trying to reach central Europe ahead of winter – with some resorting to extreme measures to complete the journey.

The facilities that have been set up over the past week have a capacity of 1,000 to serve one of the busiest bottlenecks in the country, near the Greek border town of Idomeni.

Syrian English literature student Hussam Jaban, 21, told The Associated Press he swam to a Greek island from the Turkish coast to avoid paying smugglers and keep enough money for the mainland journey through Europe.

“There were 13 of us and we all made it,” Jaban said, moments before crossing into Macedonia on foot.

“We had a small inflatable boat for a 3-year-old child and we pushed it along.”

Jaban said it took him four hours to swim from the small Turkish resort of Kas to the eastern Greek island of Castellorizo.

The numbers of migrants arriving to Greece’s islands exploded over the summer, with more than 5,000 people per day making the Aegean Sea journey in September, according to the United Nations Refugee Agency, UNHCR.

About 70 percent of the arrivals are from Syria and most continue their journey through Macedonia, Serbia, Croatia and Hungary toward the more prosperous northern European nations.

Some 4,500 people just arrived at the Idomeni crossing, most of them by bus from Athens, Greek police said.

Many often arrive at the same time, overwhelming border control officials who can’t process all in one day and are often forced to leave some waiting at the border overnight.