Turkey announced last week that it would no longer prevent refugees from reaching the European Union, despite a 6 billion euro ($6.7 billion) deal in 2016 when Ankara agreed that any migrants hoping to cross into Greece would be sent back. Turkey’s decision to open its borders last week would technically allow any economic migrants and refugees to attempt to enter the EU.

“Most of those on the move are men,” the International Organization for Migration (IOM) said Sunday, adding that there are also “many family groups traveling with young children” heading to the Greek border.

Ten thousand people at Evros, the Greek region that borders Turkey, were prevented from entering into Greece over the weekend, the Greek ministry for foreign affairs said Sunday. More than 1 million refugees and migrants arrived in Greece in 2015 and early 2016 — the height of the crisis and before the deal with Turkey came into place, according to the UN Refugee Agency.

Greece has now decided that it will not be accepting any new asylum applications for one month.

“Once more, do not attempt to enter Greece illegally — you will be turned back,” Prime Minister Kyriakos Mitsotakis of Greece said Sunday.

Some migrants are also looking to arrive in Europe by crossing the Turkish border with Bulgaria. Others have been seen boarding a rubber dinghy to arrive in Greece through the island of Lesbos, Reuters reported.

European foreign affairs ministers are due to have an emergency meeting in Brussels this week. “The European Union needs to redouble efforts to address this terrible human crisis with all the means at its disposal,” the EU’s foreign policy chief Josep Borrell said in a statement.

The large influx of refugees into Europe in recent years has had its origins in the many conflicts taking place in the Middle East, in particular in Syria. Since 2011, rebel forces have fought against the regime of Syrian President Bashar Assad. The latest escalation of this civil war is taking place in the region of Idlib, where Syrian government forces, supported by Russia, have been trying to regain control of the area from jihadist groups and Turkish-backed rebel factions.

According to the BBC, 33 Turkish soldiers were killed in airstrikes in the Syria province of Idlib last week. President Tayyip Erdogan said that European countries were failing to support Turkey in this conflict.

Furthermore, Turkey has also argued it has reached overcapacity with almost 4 million refugees from Syria, Afghanistan and other countries, at a time when its economy faces some uncertainty.

“The threat of a wave of refugees heading to Turkey from Idlib and then on to Europe should concentrate the minds of politicians in Europe,” Timothy Ash, senior emerging markets strategist at Bluebay Asset Management, said in a note Friday. “Erdogan wants Europe to get him out of his trench in Syria,” he later added.

Erdogan is due to visit Russia on Thursday, according to Reuters.

“The ongoing renewed fighting in and around Idlib represents a serious threat to international peace and security. It is causing an untold human suffering among the population and having a grave impact on the region and beyond,” Borrell also said.