Fights have broken out among migrants on the Greek island of Kos, where authorities are struggling to contain increasing numbers of people fleeing the conflict in Syria.
Hundreds of protesting migrants demanding quick registration began blocking the main coastal road in the island's main town, staging a sit-in.
They chanted: "We want papers, we want to eat."
Hundreds of people arrive on Greece's eastern Aegean islands every day, many after fleeing conflict in Syria and Afghanistan. Authorities, locals and charity groups are struggling to provide registration, food and shelter to the new arrivals, many of whom are children.
Many of those on the popular tourist destination of Kos had been camping in the main town's parks and squares.
An attempt to have them relocated to a stadium for registration unravelled, with fights breaking out among some of the 1,500 people gathered in a long, crowded queue in the stadium.
Hundreds fled as police spayed the migrants with fire extinguishers and using batons.
Similar protests and tension have occurred on several of the islands bearing the brunt of the migrant influx in recent weeks, including Lesbos, where the majority of new arrivals land.
Greece's coast guard said it had rescued 329 migrants in seven separate search and rescue incidents off the coast of Lesbos and Kos in the 24 hours from Monday morning.
Those figures do not include the hundreds more who reach shore themselves in inflatable dinghies from Turkey, making their own way to the islands' main towns for registration.