Severe storms that struck the Athens area brought exceptionally heavy rainfall, with around 150 litres per square metre recorded in some locations, local media reported on Friday.
The extreme weather, which included hurricane-force winds and intense downpours, caused widespread flooding in parts of the Attica region, disrupting transport and damaging infrastructure, according to the reports.
In some neighbourhoods, rainfall totals approached nearly three times the typical monthly amount for January, overwhelming drainage systems and inundating streets and buildings.
Greek authorities have issued warnings to residents and urged caution as floodwaters remain high and conditions are expected to persist in the coming hours.