President Recep Tayyip Erdogan announced he was allowing people through its crossing points on Friday following an escalation of fighting in Idlib province and the death of 33 Turkish soldiers in an airstrike.
Almost immediately thousands of people began massing in the border zone between the two countries, prompting Greek authorities to fire tear gas and stun grenades to push them back from the fences.
On Sunday evening, Turkish interior minister Suleyman Soylu announced that 100,577 people had left Turkey through the city of Edirne, more than double the number that had passed through by end of Saturday.
The huge increase in numbers has increased the pressure on Greek authorities at crossing points along the 212km border.
Monitors for the UN’s International Organisation for Migration said at least 13,000 people had gathered at the formal border crossing points at Pazarkule and Ipsala as well as other informal crossings.
“Most of those on the move are men but we are also seeing many family groups travelling with young children,” said IOM Turkey chief Lado Gvilava.
“We’re distributing meal boxes and other basic supplies in the city but the temperatures are dropping to nearly zero and the wind is quite bad so we’re concerned about these vulnerable people who are exposed to the elements.”
Other migrants attempted to make the short sea crossing from the Turkish coast to the Greek islands. At least three dinghies carrying migrants arrived on the Greek island of Lesbos on Sunday morning.
Greek deputy defence minister Alkiviadis Stefanis said there were around 9,600 attempts to illegally cross Greece’s border during the night.
Officials said they arrested 66 migrants on Friday and 70 on Saturday. Seventeen of those, all Afghans, were jailed for entering the country illegally, the first such sentences since 2014.
Under a €6bn (£5bn) deal in 2016, Turkey agreed to stem the tide of refugees to Europe in return for financial aid.
However, nearly 950,000 displaced civilians have been pushed towards the Syrian-Turkish border amid a military escalation in Idlib province.
On Saturday, Mr Erdogan said Turkey would not stand in the way of refugees and migrants already in the country who hope to head to Europe.
“We will not close the gates to refugees,” he said. “The European Union has to keep its promises. We are not obliged to look after and feed so many refugees.”
Additional reporting by agencies