Two thieves broke into the Renoir Museum in Cagnes-sur-Mer, France, on Tuesday.

They stole four paintings by Pierre-Auguste Renoir.

They cut through a fence and entered through a window.

The theft took less than three minutes.

As they fled, the thieves left two paintings in the museum garden.

The two missing works are "Portrait of Madame Colonna Romano" and "Young Woman at the Well."

The recovered paintings are "Portrait of Madame Pichon" and "Coco Reading."

Mayor Bryan Masson said the four works are worth about 9 million euros.

That is about $10.5 million.

The museum is in Renoir's former home.

He lived there until his death in 1919.

The alarm went off at 5:48 a.m., and police arrived five minutes later.

Their quick response forced the thieves to flee, the mayor said.

The Marseille prosecutor has opened an investigation into theft by an organized gang.

At least two of the stolen works have a difficult past.

Authorities believe Nazis took "Young Woman at the Well" during World War II.

It was found again in 1949.

A German officer gave "Coco Reading" to a soldier at the end of the war.

Germany returned it to France in 1994.

Art theft expert James Ratcliffe said a lack of money is the main problem for museums.

This is especially true for smaller ones.

He noted that the recent Louvre theft showed criminals that museums are easy targets.

Ratcliffe added that the thieves will find it almost impossible to sell the Renoirs.

They cannot easily approach art dealers with stolen works.