Thousands of refugees and migrants surged from Turkey's western frontier on Sunday, attempting to enter Greece by land and sea after Turkey said its borders were open to those wanting to reach Europe.

Turkey's decision to ease border restrictions came amid deadly fighting during a Russia-backed Syrian government offensive into Syria's northwestern Idlib province.

Dozens of Turkish troops have been killed and nearly one million Syrian civilians have fled the fighting towards Turkey.

Turkeyish President Recep Tayyip Erdogan's decision to open his country's borders with Europe made good on a longstanding threat to let refugees into the continent.

His announcement marked a dramatic departure from the previous policy of containment, an apparent attempt to pressure Europe into offering Turkey more support in dealing with the fallout from the Syrian war to its south.