Four paintings by Pierre-Auguste Renoir were stolen from the Renoir Museum in Cagnes-sur-Mer, in southern France, on Tuesday morning. Two of the works were later recovered after being abandoned in the museum’s gardens.

The missing paintings are Portrait of Madame Colonna Romano (1910) and Jeune fille au puits (1886). The recovered works are Portrait of Madame Pichon (1895) and Coco Lisant (1905).

Local Mayor Bryan Masson said the thieves entered the museum gardens after cutting through a fence. They then cut through structures holding the paintings’ frames in place. The alarm sounded at 05:48 local time, and police arrived within five minutes, he said.

Masson said the suspects appeared to be well-equipped and well-informed. They were reportedly wearing helmets, gloves and combat gear and carrying an electric knife and hacksaw. Investigators also found two zip-up bags at the scene that may have belonged to the suspects.

Each of the four paintings was valued at €9m, according to the report. “It’s Renoir’s, it is priceless, you cannot sell it like that,” Masson told reporters at the museum.

The Renoir Museum is housed in the artist’s last home and contains 12 of his artworks, along with personal items including his easel, wheelchair, photographs and letters.

The theft is the latest in a series of high-profile art heists in Europe. Masson called for greater financial support to improve security at museums and protect artworks from what he described as increasingly organised and determined criminals.