A Valentine’s Day mural by street artist Banksy has been vandalised.

The artwork, which was first spotted on the side of a building in Bristol on Thursday, showed a young girl firing a slingshot.

Banksy confirmed he was behind the piece by posting a photograph on his official Instagram account and website on Friday morning.

However, a picture shared on social media hours later showed the words “BCC W***ERS” had been scrawled in pink across the artwork.

The graffiti appears to be a reference to Bristol City Council.

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AFP PHOTO / NIKLAS HALLE'N -- RESTRICTED TO EDITORIAL USE, MANDATORY MENTION OF THE ARTIST UPON PUBLICATION, TO ILLUSTRATE THE EVENT AS SPECIFIED IN THE CAPTION -- (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images) NIKLAS HALLE'N AFP/Getty Best of Banksy Barbican Centre, London The second of the two murals painted by on the Barbican Centre, London PA Best of Banksy "Cans" London AFP/Getty Best of Banksy 'Sorry' East London AFP/Getty Best of Banksy 'Napalm, (Can't Beat That Feeling)' Displayed in an unauthorised 2006 retrospective in London Getty Images Best of Banksy Calais, France A child with a suitcase looking through a telescope with a vulture perched on it, in tribute to migrants and refugees on a beach in Calais AFP/Getty Best of Banksy 'Banksus Militus Vandalus' Displayed in an unauthorised 2006 retrospective in London Getty Images Best of Banksy London Artwork depicting former British Prime Minister Winston Churchill AFP/Getty Best of Banksy 'Donkey Documents' Moved from Jerusalem PA Best of Banksy 'A Girl with a Pierced Eardrum' A defaced piece of art on a wall in the city of Bristol, at Hanover Place PA Best of Banksy 'Sperm Alarm' Banksy's name is reflected in the glass covering his piece. 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One local resident who spotted the vandalism responded: “It’s a real shame, but it was always going to happen, unfortunately.”

Kelly Woodruff, the daughter of Edwin Simons, who owns the rented home on which the artwork appeared, had earlier expressed concern at the potential for Storm Dennis to damage it.

In December Banksy created a modified nativity scene at a hotel in Bethlehem, depicting Jesus’ manger in front of the separation barrier in Israel.