The nine suspects are expected to appear before a judge on Monday, while a further seven are being questioned in custody.
“These are people without scruples, delinquents who won't stop at anything,” Interior Minister Bernard Cazeneuve told Europe 1 radio, before going on to praise the rapid action of the police in “putting a stop to the vile acts of these individuals”.
“Every neighbourhood in Cannes has been hit by the disaster, Cannes mayor David Lisnard told reporters on Sunday.
“Many shop windows have been damaged or even smashed to pieces by the force of the water or by street furniture which was carried along by the water, and we are endeavouring to protect property – after people, of course," said the mayor.
Two squads of riots police have been deployed to prevent further looting, the head of police for Alpes-Maritimes, Adolphe Colrat, told France Info.
The violent storms and flooding along the French Riviera killed at least 18 people on Saturday night and another four are still missing in what one local official described as "apocalyptic" scenes.
Hope was running out on Monday that four people still missing after devastating floods in the French Riviera, could be found safe and well.
On Monday, Britain's foreign office confirmed that one UK national was among the 17 victims of the floods.