ATHENS, Greece (AP) — Greece's fire department says rescue crews are searching for six people reported missing in the western Athens area following major flash flooding that left at least 14 people dead.

The search and rescue operation Thursday was being conducted in the Mandra area on the western outskirts of the Greek capital, where the previous day's flooding following a severe storm that turned roads into raging torrents of mud and debris and saw cars slam into buildings.

The government has declared Thursday a day of national mourning.

Schools in the area remained closed for a second day, while the Athens municipality shut down another 20 schools located near streams and creeks as the capital was lashed with more bad weather.