The removal of a south London street sign featuring work by the elusive artist Banksy has been reported to police, the area's council says.
The piece of street art - a red stop sign with three military drones on - was unveiled on the corner of Commercial Way, Peckham, on Friday.
But within an hour it was removed by a man with bolt cutters as witnesses took photos.
One gallery owner has said the artwork could be worth up to £500,000.
Southwark Council's Jasmine Ali said the incident had been reported to the Metropolitan police.
"I have every confidence they will get it back. We are not just talking about a street sign here, it is a work of art which was put there for the community.
"It is street art and it is for the people," she said.
On Friday, one man described how he "watched in awe" as the sign was taken down at about 12.30 GMT.
Alex, 26, said no-one knew what to do and "we just watched it happen".
One man, carrying a banana, held a Lime bike steady for another, who reached up and cut the artwork free.
Wrenching it off the post, he then ran down the street and out of sight.
While the incident has been reported to the Met Police, art gallery owner John Brandler questioned whether it was a "publicity stunt".
"I think it if it came up at auction it would be worth £250,000 to £500,000.
"It could easily be higher. The media attention has made it more valuable.
"If I am being cynical, I think he did it as a Christmas present for someone."
Banksy's Instagram followers widely interpreted his latest work as calling for a ceasefire in the Gaza Strip after he confirmed the authenticity on his social media.
Prof Paul Gough, vice-chancellor of Arts University Bournemouth, explained Banksy's work "always thrives on that ambiguity".
"He rarely puts art there by accident," Prof Gough said.
"There are some 40,000 comments on his Instagram - yet he follows nobody - and you get a whole range of interpretations."
'Difficult to find a buyer'
Ulrich Blanche, a street art expert with Heidelberg University, said Banksy's thought-provoking work is usually seen as making a "political statement".
He believes the location of Commercial Way, next to a funeral directors and the drones flying away paints a picture of the global arms trade.
But, although this Banksy will be worth hundreds of thousands of pounds, he adds it might not be so straightforward to find a buyer.
"It is worth quite a lot of money." Mr Blanche added.
He said that whoever has it may find it difficult to sell because of how they came by it.
Banksy has installed other pieces this year including Valentine's Day Mascara, a mural weighing 3.8 tonnes, which appeared on the side of a house in Margate, Kent, on Valentine's Day.
It depicted a 1950s' housewife with a swollen eye and missing tooth, wearing an apron and yellow washing-up gloves, and throwing a man into a chest freezer.
In September it was placed in the foyer of The Art of Banksy exhibition in central London, where it can be viewed for free.
Four years ago Banksy set up a shop in Croydon featuring the stab vest he designed for Stormzy's headline act at the Glastonbury Festival.
