The Greek government has begun distributing flyers to migrants living in a sprawling tent city on the Macedonian border, warning them of a critical health danger.
It says clearing the makeshift camp is a priority, and says it could be done by the beginning of next month.
Tensions boiled over in April at the makeshift migrant camp near the town of Idomeni, where migrants and refugees have been stranded since February, when Balkan countries shut their borders to anyone wanting to head north.
Last week Macedonian police fired tear gas to disperse around 50 migrants stranded in Greece who tried to pull down part of the razor wire fence separating the two countries.
Scuffles briefly broke out and Greek riot police later intervened to break up the crowd.
Greek authorities say Macedonian police fired tear gas and stun grenades to deter the group from trying to get over the razor-wire fence using blankets.
The Balkan route was the preferred gateway into western and northern Europe last year for around 1 million migrants from the Middle East and beyond.
Newshub. / NZN