Refugees and migrants, from Syria and throughout the Middle East, trying to cross the border into Hungary have been hit with tear gas and water cannons by riot police.
The closing of the Hungarian border from Serbia has seen a rise in violent clashes between authorities and those looking to pass through the country on the way to western Europe.
On Tuesday Hungary made it illegal to enter the country or damage a new razor-wire border fence. Since then the country’s courts have started fast track trials of arrested migrants.
It comes as other European nations look at taking measures to protect their borders from a surge of both migrants and refugees. Many of the migrants want to reach Germany, amid divisions within the EU over how to deal with the crisis.
The Serbian town of Horgos has proved a boil-over point with refugees and migrants involved in a tense stand-off with police on the other side of the border. The scene has seen fires burning and Serbian emergency services scrambling to help.
Some migrants threw missiles, including stones and water bottles. In response riot police sent tear gas and water cannons flying.
Serbia’s foreign ministry has protested over the firing of tear gas and water cannon into its territory, the BBC says.
According to BBC News tens of thousands of people have crossed into Hungary to enter the European Union’s Schengen zone, which in normal circumstances allows people to travel between countries without restrictions.
The Hungarian government said 20 police officers were injured by migrants trying to break through a great. It has also accused migrants of using children as “human shields”.
United Nations Secretary General Ban Ki-moon says he is “shocked” by the “unacceptable” treatment of migrants.