A manhunt is underway after thieves broke into the Renoir Museum on the French Riviera early on Tuesday and stole several paintings worth an estimated €9m, the local mayor said.Two people broke into the museum shortly before 6am ​and took ⁠four works of art, dropping one as they left, Cagnes-sur-Mer mayor Bryan Masson announced on social media.“Attacking the Renoir museum is attacking a part of the history and heritage of Cagnes-sur-Mer. These actions are particularly serious,” Masson said in his message.Local outlet Nice-Matin identified the stolen paintings as the Portrait of Madame Pichon (1895); Portrait of Madame Colonna Romano (1910); Coco Lisant (1905); and Jeune fille au puits (1886), all by the French impressionist Pierre-Auguste Renoir.Caroline d’Amat, deputy mayor of Cagnes-sur-Mer, told Le Parisien that the burglars were scared off by a police dog, arriving just minutes after the alarm went off.The heist comes just months after a raid on Paris’ famed Le Louvre art museum, making off with €88m ($102.3m) worth of jewels, including Empress Eugenie’s tiara.A police officer stands in front of the entrance of the Musee Renoir after four paintings were stolen on Tuesday morning (AFP/Getty)D’Amat told the outlet the thieves were forced to abandon two paintings in the museum garden after being spooked by the dog. She said they were still investigating exactly what was taken.Pressed on whether the robbery amounted to a “security breach”, she said: “I remind you that the municipal police arrived in five minutes; it’s hard to do better!”She said the paintings were hung on the wall in a “museum-like fashion”, sealed and secured with metal brackets.Coco Lisant was looted by the Nazi regime during the Second World War and returned to France only in 1994.The portrait of Madame Colonna Romano and Jeune fille au puits were on loan from the Musée d’Orsay in Paris, according to the museum’s website.The latest heist comes only weeks after Italian police recovered paintings by Renoir, Paul Cézanne and Henri Matisse that were stolen earlier this year from a private museum near the city of Parma.The Italian Carabinieri’s art recovery squad said in August that they had recovered Renoir’s Fish, valued at $3.5m, among the artworks stolen in March.Renoir’s most valuable works have fetched dozens of millions of dollars at auctions in the past.The Portrait de Madame Pichon, 1895 (Pierre-Auguste Renoir)Portrait de Madame Colonna Romano (Pierre-Auguste Renoir)The museum was created in 1960 in Renoir’s mansion on a hill in Cagnes-sur-Mer, near Nice, where he died in 1919.The collection on display in the museum includes 13 paintings from the master and some 40 sculptures, furniture and photographs.Art thieves in Europe are committing more violent robberies and specialist gangs have been replaced by ad hoc ​opportunists recruited through social media, pan-European police body Europol said last month.The EU last June introduced new regulations to prevent the trade of stolen and looted artefacts from any third country, but experts say incidents like these show there is still a market for stolen artworks, traded outside of Brussels’ reach.Fred Clark, partner and art law specialist at Boodle Hatfield, told The Independent that courts would expect buyers, particularly professional art dealers, to conduct “a high level of due diligence”, such as searching the Art Loss Register, when purchasing works, limiting the likelihood a purchaser could acquire legitimate title to a stolen work. He said that the paintings loaned from other museums may be covered by an indemnity from the French State, which ensures lenders are provided with protection for loss without having to fork out for costly insurance policies.“If any of the artworks were owned by the museum itself, the local municipality may have to bear the loss pending the outcome of the police investigation,” he added.In late July, two thieves posing as tourists stole two ‘priceless’ archaeological artefacts from the Musée du Pays Châtillonnais, southeast of Paris.Thieves also snatched around 20 pieces of jewellery valued at around $4.5m in total from the Musée Lalique in Wingen-sur-Moder over the summer.