OSLO, Norway (AP) - Police are still hoping for a breakthrough to recover two masterpieces by Edvard Munch stolen a year ago in a brazen daylight robbery.
Masked gunmen took "The Scream" and "Madonna" from the Munch Museum on Aug. 22, 2004, as stunned visitors looked on. Newspaper reports later said the paintings reportedly had been burned to destroy evidence, but police denied the reports.
"We are still optimistic," Morten Hojem Ervik of the Oslo police said Monday. "We have said all along that this could take time. I can't promise a prompt recovery."
The paintings are among Munch's best-known works. "The Scream," which shows a figure apparently screaming or listening to a scream, has become a 20th century icon of human anxiety. There are three other versions of the painting.
"Madonna" shows a bare-breasted young woman with her head thrown back in either anguish or abandon, ringed with a blood-red circle like a halo.
Police have charged five suspects in the theft. Three remain in custody while two were released but are still charged, said Ervik. He also said police are watching additional suspects believed to have participated in the heist in some form.
"There can be more arrests," he said.
In June, the city of Oslo, which owns the Munch Museum, offered a 2 million kroner (US$305,000; euro250,000) reward for the return of the paintings, leading to a slew of sometimes useless or marginal tips.
"There have been a lot of tips, and it takes a lot of time to check them out," Ervik said by telephone. "I wouldn't say that many were false tips, but many did not have much to offer when we checked them."
The Norwegian national treasures are also listed on the FBI's Web site for stolen artworks, with a request for tips.
The emotionally charged painting style that Munch developed was a major influence in the birth of 20th-century expressionist movement. "The Scream" and "Madonna" were part of his "Frieze of Life" series, in which sickness, death, anxiety and love are central themes. Munch died in 1944 at the age of 80.
Art experts say both the paintings are priceless, and too well known for the thieves to be able to sell.
In 1994, another version of "The Scream" was stolen from the National Gallery in Oslo and was recovered a few months later in a sting operation.