An investigation has been launched after a Celtic flag was hoisted above Glasgow City Chambers.

Video footage shows an unknown prankster replace the long-standing Saltire above the iconic building in Glasgow's George Square with a nine-in-a-row flag.

It appears they scaled the building before taking the flag down moments after raising the green and white colours above the building.

Councillors in Glasgow have hit out at the prank, with one confirming that they had spoken to the Lord Provost about the incident.

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Councillor Thomas Kerr said: "Concerned to see a Celtic flag being flown from the city chambers this morning.

"Our civic buildings are there for all Glaswegians no matter which football team you choose to support.

"I have spoken to the Lord Provost who has assured me that this matter is being investigated."

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A Glasgow City Council spokeswoman confirmed that the matter is now being investigated.

She said: "This is inappropriate. It should not have happened and we are investigating.”