There are some 10,000 people in an unofficial refugee camp in Idomeni, Greece.
Many have been living at the camp for months, essentially in limbo.
Months of waiting and desperation can make tempers flare. That's what happened last night in Idomeni, and police responded with tear gas.
Photographer Jodi Hilton, who has been reporting from the camp this week , witnessed what happened and sent us these images.
An immigrant throws rocks at Greek police at the Idomeni camp on May 18, 2016. Clashes started when immigrants commandeered an empty train wagon and pushed it toward the Macedonian border. They were stopped by Greek police, who fired tear gas and stun grenades.Jodi Hilton This migrant suffered injuries during the clashes at Idomeni camp.Jodi Hilton Families run after tear gas was fired by Greek police during the clashes.Jodi Hilton A protester walks past a fire lit during clashes at the camp.Jodi Hilton A disabled Syrian refugee wipes his eyes after exposure to tear gas.Jodi Hilton Leen Issa comforts her daughter, 11-year-old Rezan, who was suffering from the effects of tear gas exposure from clashes the previous night. Rezan had open heart surgery as a baby and still suffers from a heart condition. The family from Syria lives in tents positioned on the train tracks in Idomeni, an informal camp on the Greek side of the Greek Macedonian border.Jodi Hilton Anas Nashwati, 22, and his mother, Maryam Boura, leaving Idomeni for a new camp near Thessaloniki, the day after clashes between immigrants and Greek police ended in tear gas. The family (of three, including his sister, 16) were living aboard a train parked at the station when the clashes started. "We closed all the windows but still the tear gas came in. My mother, who has problems breathing, is still suffering. We can't live here," explained Nashwati.Jodi Hilton Jodi Hilton is covering the refugee crisis in Greece with support from the Pulitzer Center on Crisis Reporting.