A version of Edvard Munch's masterpiece "The Scream" goes back on public display this week for the first time since it was stolen four years ago but has suffered permanent damage, Oslo museum officials said Wednesday. Masked gunmen stole the work and another Munch masterpiece "Madonna" in a brazen daylight raid from the Munch Museum on Aug. 22, 2004. The paintings, considered priceless, were recovered by police just over a year later. Two men have been convicted and jailed for the raid. The two works show signs of damage despite extensive restoration. At a preview of the exhibition that opens Friday called "The Scream and Madonna Revisited," water damage to the lower left corner of "The Scream" was clearly visible, as were scrapes to both paintings. "There has been an extremely comprehensive process to restore the paintings. There was significant damage," said Gro Balas, of the city of Oslo, which owns the museum. "There is still a moisture stain on 'The Scream' that cannot be repaired." "The Scream" is probably the best known of Munch's emotionally charged works and was a major influence on the Expressionist movement. In four versions of the painting, a waif-like figure is apparently screaming or hearing a scream. The image has become a modern icon of human anxiety. The museum said it concluded during its restoration of the unsigned and undated version of "The Scream" that it was most likely painted in 1910 rather than 1893 as believed earlier. Balas and museum experts said they would keep looking for new restoration techniques.