Greek authorities used tear gas and a water cannon to repulse an attempt by migrants to push through the border from Turkey in the morning, while Turkish authorities fired volleys of tear gas onto the Greek side of the frontier.
Thousands of refugees and other migrants have been trying to get into Greece through the country's eastern land and sea borders over the past week, after Turkey declared its previously guarded borders with Europe were open.
Turkey has said it is deploying 1,000 special forces police on its side of the border to prevent Greek authorities from pushing back migrants who manage to cross into Greece.
Many have been camping out on the Turkish side, hoping to cross despite Greek insistence that its border is closed. Reporters were being kept away from the border area on the Turkish side, but saw at least one bus full of people leaving the area Friday morning. It was unclear where the bus was headed.
After months of threats, Turkish President Recep Tayyip Erdogan has now said his country will no longer be the gatekeeper for Europe. He has demanded that Europe shoulder more of the burden of caring for refugees, although the EU insists it is abiding by a deal in which it disbursed billions of euros for care in return for Turkey keeping the refugees on its soil.
His decision and its aftermath have alarmed governments in Europe, which is still seeing political fallout from mass migration that started five years ago.
Erdogan's move came amid a Syrian government offensive in Syria's northwestern Idlib province, where Turkish troops are fighting. The Russia-backed offensive has killed dozens of Turkish troops and sent nearly a million Syrian civilians toward Turkey's sealed border.
A cease-fire in Idlib brokered by Erdogan and Russian President Vladimir Putin on Thursday went into effect at midnight. It was not clear whether the agreement would also affect the situation on the Turkish-Greek border. Greek officials have repeatedly stressed that those attempting to cross the border are not refugees from Idlib, and mostly not Syrian.
European Union foreign ministers were holding an emergency meeting in Zagreb, Croatia to discuss Syria and the border situation.
EU foreign policy chief Josep Borrell welcomed the cease-fire brokered by the Turkish and Russian leaders. "Let's see how it works, that is the precondition in order to increase humanitarian help for the people in Idlib," he said.
Borrell said the EU needs to improve relations with Turkey and Russia, adding the ministers will discuss more funds for Turkey. He wouldn't provide details or say how many countries support or oppose the idea.
"Turkey is having a big burden, 4 million people, we have to understand that," Borrell said. "But at the same time we cannot accept migrants being used as a source of pressure."
Dutch Foreign Minister Stef Blok, however, said he opposed more aid for Turkey, criticizing the "cynical way" Erdogan was using refugees.
"We should not react to the pressure that Turkey is exerting on us by agreeing to more money under pressure," he said.
Austrian Chancellor Sebastian Kurz accused Turkey of carrying out an "organized attack on Greece."
In an interview with Germany's Funke media group published Friday, Kurz said: "A week ago we didn't have a humanitarian crisis in Greece, no crisis on the Turkish-Greek border and also none in Turkey. This is a planned and targeted attack, directed and organized by the state. Europe must not give in to this pressure."
Greek Foreign Minister Nikos Dendias said the situation on the borders would also be discussed at the meeting.
"We are facing a mass movement of migrants towards the borders of Greece and Europe," he said as he arrived for the talks. "Migrants who have been living in Turkey for years. We have clear proof that this population movement has been created and orchestrated by Turkey."
Greek authorities have said Turkish authorities have deliberately fired tear gas at the Greek frontier to disperse border guards and so allow migrants to enter.
Irish Foreign Minister Simon Coveney said the EU should rally around Greece.
"The European Union needs to act collectively, we cannot allow one member state or two member states to carry an unfair burden," he said as he arrived for the Zagreb meeting.
However, he said it was unacceptable for Greek police to fire rubber bullets at migrants.
"We've got to treat people as human beings," he said. While I accept there are pressures on security forces and police officers on the border there because there has been panic... I think we have to act with restraint."
On the Greek side of the border, authorities were using locals with better knowledge of the terrain to apprehend those who manage to cross, either by cutting holes in the border fence or by crossing the Evros river — Meric in Turkish — that runs along most of the border.
"We were born here, we live here, we work here, we know the crossings better than anyone," said Panayiotis Ageladarakis, head of the community of the border village of Amorio.