Story highlights The death toll rises to 20 as officials warn people not to travel

In some areas, as much as 7 inches of rain fell in three hours

Photos and video on social media show torrents of water flowing through Cannes

(CNN) Horrific accounts of people drowning in a retirement home and being trapped in a road tunnel by floodwater have emerged after the French Riviera was hit by extreme downpours.

Rainfall on an "exceptional scale" set off flash floods that wreaked havoc along France's southeastern Mediterranean coast late Saturday. A representative of the French-Alpes Maritime region police said Monday that 20 people are confirmed dead and two missing as a result of flooding.

"A man in his sixties was found dead earlier on Monday in the parking lot of his in residency in Mandelieu-la-Napoule. Another victim was just found dead in Cannes" the representative said.

Photos: Flooding hits French Riviera Rescue workers pump water out of a garage in Mandelieu-la-Napoule, France, on Monday, October 5. Rainfall on an "exceptional scale" set off flash floods that have wreaked havoc along France's southeastern coast. At least 19 people are dead. Hide Caption 1 of 11 Photos: Flooding hits French Riviera A woman cleans mud-covered furniture and objects from a house in Mandelieu-la-Napoule on October 5. Hide Caption 2 of 11 Photos: Flooding hits French Riviera A man cleans a house in Biot, France, on October 5. Hide Caption 3 of 11 Photos: Flooding hits French Riviera Sea lions swim in muddy water at a zoo in Antibes, France, on October 5. Hide Caption 4 of 11 Photos: Flooding hits French Riviera Rescue workers help clean a house in Biot on October 5. Hide Caption 5 of 11 Photos: Flooding hits French Riviera A man walks by cars piled up from floodwaters in Mandelieu-la-Napoule on Sunday, October 4. Hide Caption 6 of 11 Photos: Flooding hits French Riviera A statue of the Virgin Mary stands in water at the entrance of an underground parking garage in Mandelieu-la-Napoule on October 4. Hide Caption 7 of 11 Photos: Flooding hits French Riviera Firefighters stand next to an overturned car in Mandelieu-la-Napoule on October 4. Hide Caption 8 of 11 Photos: Flooding hits French Riviera A Ferrari is seen in the middle of debris near Cannes, France, on October 4. Hide Caption 9 of 11 Photos: Flooding hits French Riviera A man carrying his bicycle tries to make his way through floodwaters in Biot on October 4. Hide Caption 10 of 11 Photos: Flooding hits French Riviera Cars are parked on a flooded street in Nice, France, on Saturday, October 3. Hide Caption 11 of 11

As much as 180 millimeters (7 inches) of rain in a span of three hours inundated parts of the Alpes-Maritimes district late Saturday, authorities said. The area is home to famous seaside resorts such as Nice, Cannes and Antibes.

Seriously though, this is the state of Cannes' main thoroughfare right now pic.twitter.com/xk2V429l9X — Stuart Dredge (@stuartdredge) October 3, 2015

Three people were killed in a retirement home in Biot, a community near Antibes, and another person was killed on a road in Cannes, according to authorities.

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