Helicopters and lifeboats have been deployed to reach hundreds of stranded villagers in central Greece, as the death toll from deadly flooding rose to seven, authorities said Friday.

Firefighters worked alongside the army to reach villages cut off by rising water levels, which have transformed roads into rivers and left houses submerged in the central Thessaly region.

"We almost died yesterday, we didn't have drinking water or electricity", Mina Mprakratsi told AFP from a lifeboat, after being evacuated from her flooded house on Friday.

Fierce storms have battered Greece, Turkey and Bulgaria following a period of extreme heat and devastating wildfires — the kind of extreme weather climate experts say is becoming more frequent because of human-induced climate change.

Two elderly women and a 69-year-old man were reported dead Thursday, bringing the death toll to seven after torrential rains lashed parts of central Greece from Monday evening to Thursday.

"It's one of the most difficult moments of my life, the water came into the house yesterday evening (Wednesday), the children are with a neighbour", local farmer Eleftheria Kotarela told AFP.

At least six people were reported missing in the Magnesia and Karditsa areas, 330 kilometres (205 miles) north of Athens.

"It is almost certain that other people will be found dead", said Christodoulos Makris, a farmer who fled to a neighboring village by tractor on Thursday.

'Extreme phenomenon'

Storm Daniel, which has lashed the country for several days, has been called an "extreme phenomenon" by Greek Prime Minister Kyriakos Mitsotakis.

Flooding affected the port city of Volos, and the towns of Karditsa and Trikala further inland and several villages, after more than a year's worth of rain fell in 24 hours this week.

Nearly 200 tourists stranded in central Greece have been evacuated by boat in recent days, firefighters said.

The heavy rains and flooding follow devastating fires in Greece this summer that killed at least 26 people.

As the world warms, the atmosphere contains more water vapor which increases the risk of heavy precipitation in some parts of the world, notably in Asia, Western Europe and Latin America.

Combined with other factors such as urbanization and land-use planning, these more intense rainfall events contribute to flooding.

Severe flooding in neighboring Turkey and Bulgaria this week left 12 people dead.