Violent clashes on the Serbia-Hungary frontier have provoked Budapest to order a 30-day suspension of the Roszke-Horgos border crossing, Serbia’s foreign ministry reports.

Our correspondent on the scene says protesters were throwing sticks. The Hungarian authorities responded with water cannon and tear gas.

At least 20 policeman and two children are reported to have been injured as a result of the clashes.

The Rozke-Horgos crossing is one of the main entry points into Hungary, the European Union and the border-free Schengen Zone.

Budapest sealed the frontier to migrants on Tuesday and reports suggest the process could be repeated on the border with Romania.

Today (September 16), Bucharest is believed to have summoned the Hungarian ambassador to discuss extending the border fence.

With the onset of violence, Hungary urged Serbia to act against migrants “attacking” its police force.

“This attack is coming from Serbia,” said Hungarian foreign minister, Peter Szijjarto, “Therefore I firmly ask my Serbian colleague to act immediately against this aggressive group of migrants,” he said in a phone interview with public television.

Budapest has called on migrants to stay in Serbia and apply for asylum there. However the United Nations says the country does not have the capacity to house the thousands being turned away from Hungary.

Some have managed to cross the border. Hungarian state media say a number have been detained and are facing criminal proceedings for illegal entry into the country.