The heavy rainfall is expected to continue for several days
At least 15 people have died in Greece after the central Mediterranean was hit by heavy flooding and violent storms.
Roads around the country were turned to muddy torrents and homes half-submerged by heavy rainfall that is expected to continue for several days.
Walls have been swept away, buildings collapsed and roads filled with rubble, as cars and trucks were thrown across streets and into fences.
Among the worst affected areas were the towns of Mandra, Nea Peramos and Megara, in semi-rural areas close to Athens, as well as the Pindus mountain range where Mount Olympus is located.
“This is a biblical disaster,” Mandra mayor Yianna Krikouki told state broadcaster ERT. “Everything is gone.”
The bodies of some of those killed were recovered by coastguards, and authorities believe at least two men - in their 50s and 80s - were lifted from their homes by the waters and swept into the sea.
Older people who were found dead inside their homes were also among the casualties.
Tornadoes were also reported in Italy and the Turkish coastal city of Antalya. In Greece rainfall has hit an average of 50mm and locally up to 400mm.
A state of emergency was declared in the small Aegean island of Symi, close to the Turkish coast, after heavy rains flooded homes and shops and created electricity cuts when the local power station was flooded.
Grigoris Stamoulis, the mayor of Nea Peramos on the east coast, told television reporters that "practically the entire town" had been overcome by the waters.
"I don't think we've ever seen such flooding before," he said.
It is thought that poor infrastructure has worsened the situation in a country where torrential rain is uncommon.
More intense rainfall is expected in Greece over the coming days, as well as in the Alps, Montenegro and southern Italy.