About 35 soldiers have reportedly marched onto a floodplain site on the east bank of the River Evros near the town of Feres on the disputed border between Turkey and Greece.
Special forces and infantry set up a camp with a small Turkish flag flying from a tree and rejected Greek demands to withdraw.
Longstanding disputes over the position of the border arise from the fact the Evros River, which marks it out, often shifts its course.
The movement leaves land that is technically part of Greece to the river’s east, and land that is technically part of Turkey to its West.
The incursion took place on Friday (AEST) and was reportedly a response to a Greek army survey of the 1.6-hectare site as part of plans to build additional border fences.
Turkey currently hosts more than four million refugees from Syria and other countries affected by conflict in the region.
Earlier this year around 10,000 people gathered at the Greek-Turkish border after the government in Ankara announced it would no longer stop them trying to cross.
Pictures and videos at the time showed refugees attempting to make the perilous crossing across the Evros River and into Greece.
In March, Bulgarian authorities, at the request of Greece, opened the Ivaylovgrad Dam upstream to widen the river and make it more difficult to cross.
Relations between Greece and Turkey have long been tense, but have been particularly so since the Turkish invasion of Cyprus in 1974.
The invasion was launched purportedly to stop the military junta in Greece establishing a union between Greece and Cyprus, whose population included both Greek and Turkish Cypriots.
The subsequent occupation, which displaced around 200,000 people on both sides of the island, remains in place today and is considered illegal under international law.
Turkey’s provocations towards Greece have mounted under hardline President Recep Tayyip Erdogan.
Four times in recent weeks, Greek soldiers and German border agency staff have been shot at over the border and Turkish F-16 fighter jets have frequently had to be chased out of Greek airspace.
Greece is reportedly trying to de-escalate tensions through diplomatic channels and has not yet made an official response.
This article first appeared on The Sun and was reproduced with permission.
Originally published as Turkey snatches land from Greece