The European Union (EU) has pressed the panic button amid the ongoing avalanche of migrants from the Middle East threatening to overwhelm the continent.

This has prompted European Council president Donald Tusk to warn that Europeans are in a "race against time."

"Let there be no doubt, the future of Schengen is at stake and time is running out. The clock is ticking, we are under pressure, we need to act fast," Tusk said on Thursday, referring to Europe's border-free travel zone.

"Without effective border control, the Schengen rules will not survive. We must hurry, but without panic," he added as quoted by the Daily Express.

Tusk spoke as Sweden dramatically sealed its borders, breaking ranks with other European countries. Denmark looks set to follow.

In the east, Slovenia began constructing a razor-wire fence along its border with Croatia.

Nearby Hungary has already built more than 120 miles of fence on its borders with Serbia and Croatia.

Bulgaria and Greece have also erected fences on their borders with Turkey to keep migrants out.

Meeting in Malta, a summit of European and African leaders failed to reach an agreement on how to deal with African asylum seekers.

In Germany, a key ally of Chancellor Angela Merkel criticised her handling of the migration crisis, describing her as a "careless skier" who has triggered an "avalanche."

German Finance Minister Wolfgang Schaeuble said: "I don't know if we are at the stage where the avalanche has hit the valley or whether it's at the stage where it's still at the upper end of the slope."

In Poland, more than 50,000 Poles poured into the streets Wednesday evening, marching with flags and slogans like "Stop Islamisation" and "Great Catholic Poland" on the anniversary of Poland's return to independence after World War I.

They held 11 demonstrations throughout the day in Warsaw greeted by police in full riot gear. There were some minor skirmishes, but no injuries reported, according the WND.

"God, honour, homeland," the protesters chanted as they marched under a sea of red-and-white Polish flags, the Telegraph reported. The protesters trampled and burned an EU flag.

Poland's outgoing government has agreed to accept about 7,000 migrants from Syria and Eritrea, angering many Poles.

Germany is accepting at least 1 million migrants from Syria and other countries in the Middle East and Africa. France has agreed to take 22,000, Britain 20,000 and Spain 17,000. Sweden has already taken in more than 40,000 Middle East migrants this year while Greece has welcomed 88,000, according to Inquisitr.com.

American author Pamela Geller has warned that Europe could face a civil war if European countries continue to accept migrants despite growing opposition from their own people.

Meanwhile, the King of Sweden is opening his palaces to the migrants. King Carl XVI Gustaf was reported to be considering letting migrants stay in his unused palaces as his country has run out of available housing for the thousands of migrants it has accepted. The king has 16 estates across the country, many of which remain unused, the Daily Caller reported.