Refugees and migrants are dying of exposure as a result of the bitterly cold weather that has hit Greece and the Balkans, the United Nations warned on Friday.

Heavy snow and sub-zero temperatures have hit the region, bringing misery to refugees stuck in camps on the Aegean islands, migrants living rough in Serbia and others tramping through mountains and forests near the Turkish border.

More than 60,000 refugees and migrants have been stuck in Greece since Balkan countries closed their borders last spring. Of those, 15,000 are stranded on five islands in the Aegean.

The UN’s refugee agency said there had been five deaths so far from the cold. Two Iraqi men, a Pakistani man and a young Somali woman died close to the Turkish border with Bulgaria, while a 20-year-old Afghan man died after crossing the Evros River on the Turkish border with Greece.