A woman was found dead in a basement flat in the southern city of Argos, in the Peloponnese, which was flooded after heavy rainfall, fire officials said Monday.

"The woman was around 60-years-old and probably of Serbian origin," a spokeswoman for the fire department told AFP.

Argos was flooded after an intense downpour that started late on Sunday. A state of emergency was declared, the spokeswoman added.

Weather conditions improved Monday, but 20 teams comprising 40 firefighters remained on location.

"It was a nightmare, all of the night. Argos was brutally hit by something we hadn't experienced before, it was a waterfall falling from the sky," Argos mayor Dimitris Kabossos told local tv station Antenna.

Flooding also occurred in the nearby cities of Korinth and Kiato, while power cuts affected all of the Peloponnese.

"The Peloponnese was the area worst hit (by this spell of bad weather)," the spokeswoman confirmed.

In late November, four people died after heavy rainfall in the tourist island of Rhodes, in the eastern Aegean.