More than 800 people have been rescued over the past two days from severe floods in Greece, local officials said, after extreme rainfall turned streets into deadly rivers, tore down buildings and bridges and left whole villages submerged.

The rainstorms also hit neighboring Bulgaria and Turkey, killing at least 14 people across the three countries, including four in Greece.

The Greek region of Thessaly, the country's agricultural hub, has been hit hardest by what government spokesperson Pavlos Marinakis called "the biggest flood phenomenon that our country has ever experienced."

The port city of Volos, the surrounding mountainous Pelion area and the cities of Karditsa and Trikala were among the worst affected areas.

The downpour has lasted days, but is expected to weaken from Thursday afternoon, according to Greece's meteorological service. Rescue operations are now underway to try to reach those left stranded by the floodwaters, which have exceeded two meters (6.5 feet) in some parts of the country.

Videos posted by Greek news outlets and on social media have shown residents in villages near the city of Karditsa forced to swim to safety after their homes were inundated. Other villagers were seen climbing onto their roofs -- the only part of their homes not submerged by water -- to call for assistance.

Five villages near Karditsa have been cut off entirely by the flooding and at least six people are missing, Greek civil protection minister Vassilis Kikilias told reporters Thursday.

"The villages of Proastio, Agia Triada, as well as the villages of Palamas, Megala Kalyvia and Kalogriana, are blocked, the waters are at a great height and superhuman efforts are being made to approach and free the residents," said Kikilias.

Kikilias said that 885 people have been rescued over the past two days, saying that the pace of the evacuation efforts was hampered by the ferocity of the downpour.

"I want to assure you that there is no means, no action and no effort that could or can be made to evacuate sooner and more safely the people who have been suffering for 48 hours that was not done," he said.

Kikilias added that rescue teams comprising hundreds of staff are working to evacuate those stranded by the floods, with helicopters deployed to help those the boats cannot reach.

Government spokesman Marinakis told reporters that the fire service had received more than 5,000 calls for assistance. The Greek army is assisting with rescue efforts.

Police have banned civilians from driving in several parts of Thessaly, after floodwaters were seen sweeping cars from the roads.

Marinakis said the Attica region, where the country's capital Athens is located, experienced nearly three times the average annual rainfall in the space of 12 hours.

The severe flooding comes just days after a two-week deadly wildfire tore through the north of the country, killing at least 18 people.

While its difficult to ascribe individual events to climate change without a scientific analysis, scientists are clear that the climate crisis is supercharging extreme weather.