Khalil Mechri, a civil defence spokesman, said "two people were swept away by floodwaters, while an elderly woman drowned in her home".

Abderazak Rahal, head of forecasting at the National Institute of Meteorology (INM), told AFP some Tunisian regions hadn't seen so much rain since 1950.

"We have recorded exceptional amounts of rainfall for the month of January," Rahal said, with the regions of Monastir, Nabeul and greater Tunis being the hardest hit.

The three deaths took place overnight from Monday to Tuesday in Monastir, the regional civil defence head told radio station Mosaique FM.

Striking images of cars stranded as torrents of water rushed through streets have widely circulated on social media.

Reports said authorities have suspended classes in several regions due to the bad weather. Transportation has also been interrupted in several parts of the country.

Mahrez Ghannouchi, another INM official, said in a Facebook post the situation was "critical" in some regions.

The tourist village of Sidi Bou Said, on the outskirts of Tunis, has recorded 206 millimetres of rain since Monday evening, according to the INM.

The dramatic downpours come as Tunisia grapples with a seven-year drought, worsened by climate change and marked by a sharp decline in water reserves in dams across the country.

The country has seen severe water stress, particularly affecting agriculture and drinking water supplies, with cuts imposed in several regions during the summer.