An impassioned plea has been made to thieves who stole Edvard Munch's famous painting The Scream on Sunday, asking them not to wreck the fragile picture.
The Scream was painted on cardboard and is very fragile
The appeal came from Gunnar Soerensen, head of the Munch Museum in Oslo, Norway, where The Scream and another Munch work, Madonna, were stolen.
"Whatever you do, don't damage them, don't destroy them," he said.
There is concern the armed thieves may panic because The Scream is too well-known to be sold.
"I would say please care for the paintings, think about these paintings belonging to all mankind - please take care of them," Mr Soerensen said.
The paintings were dropped twice when they were stolen and torn from their frames, which were left broken in the street.
The Scream, one of four versions of the iconic image, was painted on cardboard and is very fragile.
HOW THE SCREAM WAS STOLEN
1. Two masked men enter through the museum cafe
2. One man holds staff and visitors at gunpoint
3. The other man goes to the gallery and tears the Scream and Madonna from the walls
4. The two men make their escape, fleeing in a black Audi
The robbers were caught on security cameras and police are now following up a number of tips, but have no suspects or firm leads.
"We have many tips... we're keeping all possibilities
open," Oslo assistant police chief Iver Stensrud said. "It would be guesswork for me to list any motives."
Art experts have suggested the culprits would either demand a ransom from the gallery or government, or trade the pictures in deals with other criminals.
The paintings are thought to be too famous to be sold to a collector or another gallery, with so much publicity surrounding the theft.
"There's no market and there's no secret Dr No or Mr Big or anybody like that out in the Venezuelan jungle," said Charles Hill, a former British detective who helped recover another version of The Scream in 1994.
Criminal lawyer Vidar Lind Iversen said: "I think that a ransom is the most likely."
But the Norwegian government refused to pay a ransom for The Scream in 1994.
In that case, the painting was recovered after a sting operation lasting three months, which involved undercover detectives posing as potential buyers.
Mr Soerensen has defended security at the gallery during the recent robbery, saying a silent alarm went off and police arrived within minutes.
The Norwegian press was dismayed by the ease of the robbery.
"Almost as easy as robbing a kiosk," said a front-page headline in the national broadsheet Aftenposten.
Oslo's Dagbladet made the point that "some of our national treasures are too poorly protected".
Two masked men threatened a guard with a gun and tore the pictures from the walls in full view of tourists. The gang's stolen black Audi getaway car was recovered a few kilometres away.
The Scream was insured for fire or water damage - but not theft.