Thousands of migrants have broken through police lines into Macedonia at the country’s border with Greece.
Macedonian police are reported to have fired stun grenades in response.
A huge number of migrants – many of them refugees from the war in Syria – has built up in recent days, after Macedonia sealed its southern border and declared a state of emergency.
Most wish to travel through Macedonia and Serbia to reach northern Europe, via Hungary.
Macedonian security forces had been expected to let several hundred migrants in at a time on Saturday to coincide with train departures north towards Serbia and the rest of Europe.