Turkey's President
Recep Tayyip Erdogan on Saturday threatened to let thousands of refugees cross into Europe and warned
Damascus would "pay a price" after dozens of
Turkish troops were killed inside Syria.
Around 13,000 migrants have gathered along the Turkish-Greek border, the International Organization for Migration (IOM) said as several thousand migrants were in skirmishes with Greek
police firing tear gas across the frontier.
The escalating tensions between
Turkey and
Russia, who back opposing forces in the
Syria conflict, after an air strike killed the Turkish troops sparked fears of a broader war and a new migration crisis for Europe.