The Greek authorities begun the process of evacuating Idomeni, a sprawling makeshift camp housing thousands of migrants on its northern border with Macedonia, in a dawn operation on Tuesday.
Hundreds of Greek riot police sealed off the camp to journalists and activists, but police could be seen in the distance clearing tents and moving people onto buses as helicopters flew overhead.
More than 8,000 people, including many women and children, have been camped out at the makeshift site for weeks hoping for the border to reopen.
Idomeni was once a brief stopping point on the so-called "Balkan Route" traversed by hundreds of thousands of migrants last year but became a bottleneck after Macedonia closed its border in March and erected a wire fence, effectively sealing the way west. At one point more than 12,000 people lived there.
Despite sporadic clashes between police and migrants camped out at the site in recent weeks the Greek authorities said on Tuesday morning that the process had so far been peaceful and that force would not be used during the operation.
"The evacuation is progressing without any problem," said Giorgos Kyritsis, a government spokesperson for the migrant crisis.
Previous outbreaks of violence between migrants and both Macedonian and Greek security forces have seen stun grenades and tear gas fired into the camp.
However video footage from inside the camp on Tuesday morning showed people calmly packing up their belongings and tents under the watchful eyes of the police. Children played amid piles of luggage, clothes, and blankets as their families waited to board buses.
Journalists reported that several undercover security officers disguised as migrants were also working inside the camp alongside the riot police. Macedonian security forces also beefed up their presence on the other side of a razor wire fence which the camp stretches up to.
According to the Greek authorities those evacuated from Idomeni will be moved from the site over several days to state-supervised camps further south. Around 1,000 people were thought to have been bussed out of the camp by 11am on Tuesday.
Some 45,600 migrants are currently stranded on the Greek mainland according to the latest figures released by the United Nations refugee agency UNHCR.
Meanwhile another 8,000 people, who arrived after a controversial deal between Turkey and the European Union came into effect, are are being held in makeshift detention centers on the Greek islands. They will have an initial assessment of their asylum claim processed before either being returned to Turkey or sent on to the mainland.
Under the EU-Turkey agreement all migrants arriving illegally in Greece are going to be sent back to Turkey. The EU will then take one recognized Syrian refugee out of Turkey for resettlement in exchange for each Syrian deported from Greece.
However, the authorities have struggled to put the both the Turkey-EU deal and a separate Europe-wide relocation programme into effect, with implementation marred by insufficient personnel to process claims.
So far fewer than 500 migrants have been returned to Turkey. The figure is already much lower than was initially expected and the process may now be further slowed after a Greek appeals committee ruled last week that Turkey was not a safe country to return a Syrian asylum claimant to. Those who contest decisions to reject their asylum claims are entitled to lodge appeals, a process that can take over a year.
According to figures released by the European Commission in April only 615 of the 66,400 asylum-seekers pledged to be relocated from Greece had actually been moved to other EU countries.
"The current asylum process is inadequate and slow," Panos Navrozidis, The International Rescue Committee's Country Director in Greece said in a statement. "Improved resources are urgently needed to provide refugees safe and legal routes to sanctuary in Europe and to reunite with family members. The extensive backlog means that many refugees will be waiting for months before their case is heard. This is not acceptable anywhere but particularly not in Europe."
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Reuters continued to this report.