Pictures: Intense winter storm blankets Athens, Istanbul in snow

Tourist boats docked in the Golden Horn with Suleymaniye Mosque in the background at Istanbul. The suspension of flight operations at Turkey's Istanbul Airport was extended on Tuesday due to heavy snowfall, while winter weather snarled transport across the city, home to about 16 million people.

A person holding an umbrella walks among vehicles stuck in traffic in the Attiki Odos motorway, during heavy snowfall in Athens. A blanket of heavy snow covered the Greek capital, from the Acropolis hill to the coast in the south, disrupting air traffic, bringing transport to a halt and leaving scores of drivers stranded overnight in a highway.

A resident walks in a street during a snowfall in northern Athens. The snow occurred as a blast of cold air from northern Europe plunged into the eastern Mediterranean Sea. The cold air passing over the mild water generated high levels of atmospheric instability which gave rise to vigorous storms, including the rare "snownado" in Andros.

Residents are stuck in their car due to heavy snowfall in Istanbul. The Istanbul governor's office warned drivers they would not be able to enter the city from Thrace - a region stretching across the European part of Turkey to its western border with Bulgaria and Greece.

Local residents walk in the snow in the Kucukcekmece district in Istanbul.

A police car drives past the Greek parliament building, in Athens. The snow occurred amid a storm named Elpida, which means "hope." The Greek government declared a holiday in Athens Tuesday after snow disrupted road, rail and air travel. Many schools were closed.

Residents walk in a street during a snowfall in northern Athens. The heavy, wet snow snapped tree branches and triggered power outages with reports of motorists stranded in their cars for hours on highways.

Pedestrians walk during snow fall in Istanbul, Turkey.

Local residents are stuck in their car due to heavy snowfall in Istanbul.

A local resident attempts to catch a taxi in a snow-covered street of Athens.

Children play in the snow at the Kucukcekmece district in Istanbul.

Pedestrians walk in central Athens during heavy snowfall.

A woman walks in the snow at the Kucukcekmece district in Istanbul.

Cars try to make their way through Athens main avenue during heavy snowfall.

A local resident walks in the snow near the July 15th Martyrs' Bridge and the Ottoman-era Mecidiye Mosque in Istanbul.

A snow plow clears a road near the Acropolis in central Athens.

People throw snowballs each other on the snow-covered park in Istanbul.

Greek civil protection tracks clean from snow the national highway leading to the city of Athens.

The Parthenon temple is seen atop the Acropolis hill, during heavy snowfall in Athens.

A view of snow-covered Golden Horn area at Istanbul.