Turkey has declared a military offensive against the Moscow-backed Syrian regime after an airstrike that killed 34 of its soldiers.
Turkish defence minister Hulusi Akar dubbed the operation 'Spring Shield' and said Ankara had destroyed two Assad regime planes, eight helicopters, 100 tanks and six air defence systems since February 27.
It comes as president Recep Tayyip Erdogan announced the country had 'opened its doors' on Friday, causing an estimated 76,000 refugees to rush to its border with the EU.
Greek police have fired tear gas in an attempt to disperse the crowds and deny them entry to the continent as Bulgaria deployed its army to patrol its 118-mile frontier with Turkey.
Criticisms from European allies were not forthcoming after Turkish soldiers were killed, although the US said it was concerned for its ally. A NATO meeting was also called following the attack.
Migrants pictured gathered on the buffer zone on the Greece-Turkey border this morning. Erdogan said he had 'opened the doors' following the killing of 33 Turkish troops in Northern Syria by the Russian-backed regime
A group of migrants from Syria, Iraq, Afghanistan and Palestine arrive in a dinghy at Mytilene in Lesbos after crossing the Aegean Sea from Turkey
Migrants pictured in a makeshift tent as the wait in the buffer zone between Greek Kastanies and Turkish Pazarkule today
Rows of migrants pictured trudging through fields asthey walk to reach Pazarakule at the Turkish border with Greece
Migrants detained by Greek police in Neo Cheimonio, four miles past the Greek border, this morning
'We have neither the intention nor the notion to face Russia,' said the Turkish defence minister. 'Our only intention there is for the (Syrian) regime to end the massacre and thereby stop radicalisation and migration.'
He said 2,212 members of the Syrian forces had been 'neutralised', a term used to designate those killed, wounded or captured. The Syrian Observatory, a UK-based monitor, said 74 Syrian Syrian government troops and pro-Damascus fighters had been killed since February 27.
Of the two Syrian planes shot down, Syrian state news said both pilots escaped in parachutes and survived.
The Syrian regime's army has warned Turkey it will take down any planes or drones breaching the airspace over the north-west, which has been controlled for years by its ally, Moscow.
Mevlüt Çavuşoğlu, the Turkish foreign minister, said on Saturday that while there had been progress in talks between Turkish and Russian delegations, the Idlib issue would only be resolved between the countries’ presidents, Recep Tayyip Erdoğan and Vladimir Putin.
One senior Turkish official and one security official said the meeting would be held on Thursday in Moscow. The officials said the pair would discuss steps to take in Idlib and that they were expected to reach a mutual agreement.
The latest bout of fighting in Idlib has uprooted a million civilians since December, many of them women and children fleeing towards the Turkish border.
Migrants brandish their fists as they come up against barbed wire at the Turkey-Greece border today
Migrants shout and appear to be preparing to throw objects at Turkey's northwest border post with Greece today
Greece has closed its border and blocked off access with barricades and piles of barbed wire (pictured today)
Migrants run back towards the Turkish border as Greek police shoot tear gas in an attempt to disperse the crowds today
Migrants pictured on the border between Turkey and Greece today after Erdogan said he had opened Turkey's doors
The flare in tensions comes as migrants, including an Afghan mother with a five-day-old baby, have waded through the river at Kastanies to reach Greece, while at least 500 people in seven boats have landed in Lesbos, Samos and Chios in the Greek islands.
Six migrants were pictured four miles inside the Greek border this morning after they were arrested.
The EU border force, Frontex, has said it is on 'high alert' and is assisting both Greece and Bulgaria to keep their borders secure. Sofia, which deployed its army to patrol the more than 100-mile frontier, has said there have been no crossings.
Erdogan's decision to re-open the border comes as 33 Turkish troops in Northern Syria were killed by the Russian-backed Assad regime on Thursday. There was no immediate criticism of the attack from European allies, but the US said it was concerned. NATO called a meeting at the request of Turkey.
It is thought the Turkish president has opened the borders, causing scenes reminiscent of the 2015 migrant crisis, to try to pressure the EU and its NATO members to lend him support for Turkey's military operation in Syria.
A Tweet posted by Suleyman Soylu reads: 'As of 09.55 hours, the number of immigrants leaving our country via Edirne is 76,358.'
Up to 30 people were seen in Greece by Reuters reporters this morning after they forded the river at Kastanies. A small group of people were also seen making their way through fields in Orestiada, a frontier region.
Migrants crossing from Pazarkule, on the border with Greece, have clashed with riot police. Tear gas was fired into crowds including Syrians, Iranians, Iraqis, Pakistanis and Moroccans last night as asylum seekers threw stones and attempted to cut barbed wire. An estimated 2,000 further migrants also crowded into Pazarkule today.
Frontex said it had placed 400 personnel in the Greek islands, 60 officers in Bulgaria and a further contingent in the Evros region on the Greek border.
'We have received a request from Greece for additional support. We have already taken steps to redeploy to Greece technical equipment and additional officers,' they said.
Migrants pictured carrying their children as they walk on railways toward Meritsa river, near Edirne, to take a boat to attempt to enter Greece this morning
Migrants pictured walking towards the Pazarkule border with Greece this morning
Migrants, including women and children, pictured carrying their possessions as they walk to the Pazarkule border today
Migrants stumble through a frozen field this morning as they head towards the Pazarkule Turkish border post with Greece
A migrant carries bags as he walks towards the Meritsa river, Turkey, in an attempt to enter into Greece
A woman holds her toddler after making the dangerous crossing to the Greek island of Lesbos early this morning
Women and children pictured on the beach near Skala Sykamineas, Lesbos, after crossing the Aegean last night
Greece said today it had successfully blocked 9,600 attempts to 'illegally' cross its 120-mile frontier with Turkey. Of those arrested inside the country, an army officer told Reuters that they had all been Afghans, not Syrians.
The country has also accused its neighbour of actively guiding migrants. The Greek deputy defence minister, Alkiviadis Stefanis, said: 'Not only are they stopping them, but they are