At least 13,000 refugees and migrants have massed behind a wired fence on the Turkey-Greece border and hundreds of others have reached three Greek islands by boat.
After being told they would be able to enter Europe this week, some migrants were spotted trying to reach Greece by swimming across the Evros river.
But Greek police have been trying to hold back those wanting to enter, reinforcing its side of the border and firing tear gas to repel hundreds of stone-throwing migrants who attempted to force their way across, witnesses said.
Clashes have occurred throughout the weekend at the border crossing near the northeastern town of Kastanies.
Turkish President Recep Tayyip Erdogan’s decision to to ease border restrictions came amid a military escalation in Syria’s northwest that has led to growing direct clashes between Turkish and Syrian forces.
On Sunday, the UN’s International Organisation for Migration said that its staff “had observed at least 13,000 people gathered at the formal border crossing points at Pazarkule and Ipsala and multiple informal border crossings, in groups of between several dozen and more than 3,000”.
An estimated 500 others made the sea crossing from the Turkish coast to the Greek islands, with at least three dinghies arriving on the Greek Island of Lesbos on Sunday morning.
Seven boatloads reached Lesbos with more than 300 on board, while four arrived on Samos with 150 and two on Chios with a combined total of 70 to 80 people, a police official said.
Greek authorities fired tear gas and stun grenades on Saturday to prevent repeated attempts by a crowd of more than 4,000 people massed at the border crossing in Kastanies.
Turkish interior minister Suleman Soylu tweeted that 76,385 refugees had left Turkey via Edirne – the province bordering Greece and Bulgaria – as of Sunday morning.
Greece has shut its border and authorities say a few dozen arrests were made of people who managed to cross through.
Some migrants threw stones and metal bars towards the Greek side as well as hand-held tear gas canisters as tensions rose, a Greek government source said.
The country’s deputy defence minister, Alkiviadis Stefanis, told the local broadcaster Skai that there were around 9,600 attempts to illegally cross Greece’s border overnight into Sunday and that “all were dealt with successfully”.
Greek officials said they arrested 66 Afghan migrants on Friday – 17 of whom were sentenced to three and a half years in jail for entering the country illegally.
Turkish soldiers were actively helping people cross the Greek border, according to the president of the local community in Kastanies, Stavros Zamalides.
He said “Turkish soldiers with cutters in their hands were cutting the wires of the fence to lead the illegal migrants” into crossing the border.
He went on: “The attempt was thwarted by the intervention of our own patrol that happened to be passing that area on patrol at the time, and it repaired the damage in the fence.”
The intense fighting in northwest Syria has pushed nearly 950,000 displaced Syrian civilians to flee towards the Turkish border.
Despite Turkey being a strong backer of the rebels in Syria’s Idlib province, the presence of thousands of Turkish troops there has done little to stop Syrian President Bashar al-Assad’s relentless campaign to seize the last of the rebel-held territories.
In recent days, dozens of Turkish soldiers have been killed by the Russian-backed Syrian government forces around Idlib.
The Syrian government said on Sunday it was closing its airspace for any flights or drones across the country’s northwestern region, adding that any aircraft that penetrates Syrian airspace will be treated as hostile and shot down.
Mr Erdogan previously warned of an “imminent” operation against Mr Assad’s forces unless they pulled back from Turkish lines in Syria by the end of February.
But as that deadline passed on Saturday, Turkish drones bombed Syrian government targets in Idlib and the country downed two Syrian jets. Remarkably, the pilots survived.
On Saturday, Mr Erdogan said Turkey would no longer stand in the way of refugees and migrants already in the country who hope to head to Europe.
He said: “We will not close the gates to refugees.
“The European Union has to keep its promises. We are not obliged to look after and feed so many refugees.”
