Flash floods have killed at least 17 people and injured eight others at the phosphate mining town of Redeyef in southern Tunisia, the state news agency reported Wednesday.

"According to a first toll, the floods have caused 17 deaths and eight injured," mainly in Redeyef, the TAP news agency said, adding that a search was under way for people who have been reported missing.

"President Zine El Abidine Ben Ali is following with great concern the situation caused by heavy rain in the Redeyef region, which has claimed victims and done substantial material damage," TAP said earlier.

The private radio station Mosaique previously said that 15 people had died in Redeyef, about 340 kilometres (210 miles) southwest of Tunis, and reported five deaths elsewhere, but then dropped the latter figure.

An indeterminate number of people have been reported missing, according to civic associations.

The north African country's leader ordered "immediate and rapid intervention to remedy this situation... and curb the scale of the damage," TAP reported, saying that Ben Ali had instructed appropriate government departments to "very urgently provide aid to the victims of the floods and the families affected."

Tuesday's torrential rainfall reportedly measured more than 160 millimetres (6.2 inches) at Redeyef, a town of 60,000 people in a region that is normally arid.

The bad weather will continue until Friday, the national meteorological institute forecast, warning of storms with heavy rain and winds of over 100 kilometres (60 miles) an hour.