Heavy snow hit Greece early Monday, with blizzards and sub-freezing temperatures in many parts of the country, including the capital Athens and many Aegean islands.
Authorities have warned the public to limit their movements over Monday and Tuesday, while schools shifted to online classes only.
The snow was coming down thick and fast in central Athens, settling on the marble columns of the ancient Acropolis.
A thick layer of snow blanketed most of Turkey's largest city the same day.
Flurries are forecast to continue over the next few days in Istanbul, a metropolis of some 16 million spanning two continents: Europe and Asia.
Istanbul's Disaster Coordination Center AKOM says an Icelandic low-pressure system is behind the cold front and precipitation affecting the city and most of the country.
