Art theft on the rise. With five masterpieces recently being stolen from Modern Art Museum in Paris in a swift and simple raid Wednesday night shortly followed by another assault to a pensioner in his home resulting to five stolen artworks, French authorities are alarmed.

The heist at the Musee d'Art Moderne in the French capital was discovered by employees on Thursday morning when they noticed a smashed window pane. Three guards were reportedly on duty but one of the alarms was defective and other security systems were apparently overcome.

Paintings by Pablo Picasso, Henri Matisse, Georges Braque, Fernand Leger and Amedeo Modigliani were cut from their frames. These are valued at an estimated $124 million.

The most recent art theft involved two unidentified men assailing a pensioner at his home in Marseille, southern France and running away with five art works, including a Picasso lithograph. Reports say the victim was violently attacked as he opened the door after the robbers rang his doorbell.

In January, about 30 paintings -- including some by Picasso and Henri 'Douanier' Rousseau -- were stolen from a private villa in the Cote d'Azur, with a total estimated value of around one million euros.

"This is a serious crime to the heritage of humanity," Christophe Girard, culture deputy for the mayor of Paris told a news conference.

"These are key paintings by major artists," he said, adding the theft was committed by "one or more individuals who were obviously organised".

The International Police Organization (Interpol) said that officers from its headquarters in Lyon, southwest France, are currently liaising with French police investigators. Interpol adds that the images of the stolen masterpieces have also been included in their stolen works of art database. "Their inclusion in Interpol's publicly accessible works of art database will allow any legitimate buyer of paintings by Picasso, Matisse, Braque, Leger and Modigliani to determine whether their purchase would be legal and for the public to remain alert as to what has been reported stolen," said Jean-Michel Louboutin, Interpol's Executive Director.

Stolen masterpieces are rarely recovered, but three men are being tried in France for the 2007 theft of three Picassos worth more than $62 million.