At least four people died in widespread flash floods caused by heavy rains which lashed Greece overnight, the country's fire brigade said on Wednesday.
Three of the victims, all elderly, died at separate locations in the Messinia province, in the southern Peloponnese peninsula. A fourth was found dead later on Wednesday.
"I have never seen anything like it, said Panagiotis Nikas, mayor of the southern city of Kalamata.
"About 140 millimetres of rain fell in an hour this morning ... It hasn't stopped raining since yesterday at lunchtime," he told Reuters.
Seven communities in the wider region were cut off by floods, with extensive flood damage. The area is a vast plain where farming is the main activity.
Extensive damage was also reported in Greece's northern city of Thessaloniki, where television images showed cars washed out to sea or piled up from torrential rain. One woman from the area was missing.
The fire brigade reported it received more than 1,000 distress calls and rescued 74 people in difficulty.