Thousands of migrants on Saturday broke through Macedonian police barricades at the border with Greece, local media reported.
Police used stun grenades for the second time in two days in a bid to keep them out, but were overwhelmed.
Security forces had strengthened the barricades along the Greek border, where the mainly Middle Eastern migrants have been stranded in a no-man's land for several days.
Police, who have received military support since Macedonia declared a state of emergency on Thursday, stretched a second line of barbed wire between Macedonian territory and the stranded migrants, A1 TV reported.
An estimated 826 migrants deemed to be "vulnerable" — mostly women and children — were allowed to pass through in the period since the border was closed, allowing them to reach the nearby train station in Gevgelija.
But additional migrants have arrived since clashes at the border on Friday, adding to the crowd in no-man's land, local reports said. The pressure is only expected to grow, since thousands of refugees arrive in Greece each day from Turkey.
The opening of the gates for the approved group triggered a stampede, but the situation eventually calmed down and the refugees settled down for the overnight wait, huddling under nylon sheets for protection from occasional rain.
Medical teams were at the makeshift camp, mostly assisting the children, the dehydrated and the fatigued after their journey to the border followed by a long wait at the barricade, A1 said.
Black marketeers were selling a six-pack of bottled water for 10 euros (11 dollars) at the Gevgelija train stations, five-and-a-half times the regular price, the Plus Info portal reported.
From Gevgelija, the migrants hope to get a 200-kilometre ride north, to Tabanovce on the border with Serbia, the next country on their trek away from violence at home and security in the European Union.
Five trains — three regular and two emergency — with a capacity of between 100 and 700 passengers, departed from Gevgelija on Friday, the state railway said. The company also hiked the price of the ticket for the ride to Tabanovce from 330 to 600 denar (from 6 to 11 dollars).
The refugees have been proceeding from Tabanovce to Serbia without delay, Denesen Vesnik reported in its online edition Saturday.
A large group of migrants who passed through Gevgelija has arrived in Presevo, on the Serbian side, and was being settled in the new refugee centre, Belgrade TV B92 reported Saturday.
The Gevgelija-Presevo journey is just a part of the journey that the refugees, the vast majority of them from Syria, are forced to make along the so-called Balkan corridor, which takes them from Turkey, across Greece, Macedonia and Serbia to Hungary, the gateway to the European Union.
Most of the refugees hope to seek asylum in Germany and other wealthy European nations.
By Boris Babic
