Macedonian police fired tear gas and rubber bullets to push back hundreds of migrants and refugees from a border fence at a sprawling refugee camp on the Greek side of the frontier on Sunday.
Tensions that have been simmering for weeks at the sprawling Idomeni camp boiled over when more than 500 people gathered at the fence to protest and demand entry to Macedonia. More than 10,000 migrants and refugees have been stranded in Idomeni since February due to cascade of border shutdowns throughout the Balkans.
More than 1 million people fleeing conflict poured into Europe mainly through Greece in the past year. The European Union recently began implementing an accord under which all new arrivals to Greece will be sent back to Turkey if they don't meet asylum criteria.
An unnamed Macedonian official told Reuters that a large group of migrants left Idomeni on Sunday morning and stormed toward the fence.
"They threw rocks at the Macedonian police. The police fired tear gas in response," the official said.
"The migrants were pushing against the fence but standing on the Greek side of the border. The fence is still there, they have not broken through."
Aid organizations said they were treating people for tear gas exposure. The Swedish organization Lighthouse Relief, which works with refugees arriving in Greece, described a "horrific scene" in Idomeni, and said the camp was being "relentlessly tear gassed." The organization reported that border guards also fired water canons to disperse the crowd, and said that four babies and toddlers were rushed into clinic for treatment after being exposed to tear gas.
"We have injuries and are extremely busy," a senior official for medical charity MSF told Reuters. Another aid organization also confirmed injuries among the migrant population.
Witnesses said that the clashes began after a small group of individuals attempted to talk to Macedonian border guards and ask for the outpost to be opened. After they were told no, other individuals — including some with packed bags — started walking toward the fenced border.
Migrants and refugees at Idomeni are demanding that the border with Macedonia be opened, but no migrants have been allowed through for weeks.
Greek authorities have been trying to convince the population to move to reception camps, but most people have refused to move.
Last month, several hundred refugees and migrants — including people carrying babies — dashed for the Macedonian border after hearing rumors that the crossing would be reopened. People in the camp had apparently heard that journalists and Red Cross officials were going to help refugees force their way across the barricades at the border, a young Syrian refugee told the Athens News Agency.
Greek authorities broadcast messages over loudspeakers at the camp to dispel "irresponsible rumors" that the border crossing was about to reopen.
"We are trying to step up efforts to address refugees and migrants in their own language and without an intermediary," said Giorgos Kyritsis, spokesman for the government's coordination panel on migration.
In February, the Associated Press reported that the refugee camp in Idomeni is "beginning to take on a form of semi-permanence," with residents seemingly unconvinced that they will be allowed to enter Macedonia any time soon. Food and clothing donated by local Greeks are spread very thin among the thousands stranded. On Sunday, men, women and children were reportedly scrambling to receive whatever supplies they could. Hundreds of people reportedly begin lining up early in the morning to receive a sandwich for lunch.
Reuters contributed to this report.
Follow VICE News on Twitter: @vicenews