The river Artuby floods the streets in Draguignan, southern France, on Wednesday.

France ? At least 19 people were killed in flash floods that hit the back hills of the French Riviera on Wednesday and turned streets into rivers of surging, muddy water, officials said.

There was confusion about how many people were missing in the flooding that washed over picturesque towns and left them standing in yards of brown water, a press officer at the local Var region prefecture said. But probably at least 12 people were unaccounted for, the official said on condition of anonymity in keeping with her job’s regulations.

Interior Minister Brice Hortefeux, visiting the region, said the death toll, “unfortunately, may climb.”

The floods swept away cars, trees and parts of houses in a downpour that devastated the picturesque region in the hills behind a portion of the Riviera, a magnet for tourists. Coastal towns where tourists flock, Frejus and Roquebrune, also were hit.

Eleven of the deaths were in Draguignan in the Riviera back hills scattered with olive groves and small vineyards.