SERBIAN-HUNGARIAN BORDER - Hungary has closed off a railway track used by tens of thousands of migrants to enter the European Union on foot, launching a crackdown promised by the right-wing government to tackle Europe’s worst refugee crisis in two decades.

Dozens of helmeted police officers, some on horses, took up position across the track that traverses the border and has been used for months by migrants, many of them Syrian refugees, to enter the EU from Serbia. A helicopter circled overhead.

Migrants were directed to an official pedestrian border crossing around a kilometre away, where hundreds began queuing; police let small groups through a metal gate in a fence that Hungary has almost finished building along the length of its southern frontier, the EU’s external border. They boarded buses the other side.

A major flashpoint in Europe’s worst refugee crisis since the Yugoslav wars of the 1990s, Hungary has vowed to stamp control on the flow through the Balkan peninsula to the richer countries of northern and western Europe.

Police have recorded over 190,000 entering Hungary this year, many of them fleeing conflict in the Middle East and Africa, including a record for one day of 7,437 by 4 p.m. (1400 GMT) on Monday.

Prime Minister Viktor Orban, one of Europe’s fiercest critics of mass immigration, said many would face deportation under the new rules, after Hungary in July declared its impoverished neighbour Serbia a ‘safe country’ for refugees.

“In such a case, if someone is a refugee, we will ask them whether they have submitted an asylum request in Serbia,” Orban was quoted as telling private broadcaster TV2. “If they had not done so, given that Serbia is a safe country, they will be rejected.”

The influx into Europe, by boat from North Africa across the Mediterranean or across Turkey and up the Balkan peninsula, has triggered discord and recrimination in the 28-nation EU, feeding anti-immigration sentiment.

On Monday, two decades of frontier-free travel across Europe unravelled as Austria and Slovakia followed Germany in re-establishing border controls to cope with the influx. Austria said it would dispatch armed forces to guard its eastern frontier with Hungary.

On Tuesday, new laws enter into force giving Hungarian authorities the power to arrest and jail anyone caught trying to cross Hungary’s southern border from Serbia illegally, and to hold or expel asylum seekers.

Authorities will receive and process asylum requests at the border with Serbia, which is outside the EU, and send many of those who apply to camps elsewhere in the country. Those who refuse to cooperate will be held at the border and could be deported.

Those who try to smuggle themselves over the border, avoiding police, face arrest and possibly jail. Many migrants try to avoid being registered or seeking asylum in Hungary, fearing being stuck in the country or sent back there if caught elsewhere in Europe.

Drafting hundreds more police to the border, Orban told them to be humane but “uncompromising” in implementing the new law. “You will meet with people who have been deceived. You will be met with temper and aggression,” he told them.

The prospect of harsher measures and a long wait in Hungary as of Tuesday appeared to have spurred many migrants, who rushed by train, bus and taxi north through the Balkans having landed in Greece by boat and dinghy from Turkey.

“We heard the Hungarians will close the border on September 15th so we had to hurry from Greece,” 24-year-old engineering student Amer Abudalabi, from the Syrian capital Damascus, said shortly before crossing the border from Serbia. “We have not slept since Saturday morning I’m so tired. I won’t believe it when we cross into Hungary.”

Before shutting down the informal border crossing at the town of Roszke, police shepherded several thousand migrants to trains bound direct for the Austrian border, in an apparent attempt to clear the backlog by Tuesday.

Some said they had not been registered, despite the government’s insistence it is sticking to EU rules that asylum seekers must be registered in the first EU country they enter.

The United Nations refugee agency, UNHCR, said there was “no official procedure, people are just being collected” and that four hours later the trains arrived at the Austrian border.

A government spokesman denied authorities were no longer registering migrants, saying registration was taking place elsewhere.

Some of those who managed to enter Hungary were jubilant. “They will close the border,” said 25-year-old Ahmed from the Syrian city of Aleppo as he walked with a friend across the border. “Today is the end-day.”

Hours later, directed to the official border crossing, 25-year-old Firas from the Syrian port city of Latakia, stood in a long queue. “I’m very nervous,” he said. “I don’t know what we can expect in Hungary.”