A man has been spotted climbing up the Canary Wharf Tower in London.
Police say they were called at 8.35 a.m. after receiving a call about the man.
A spokesman said the man is about 400-500 ft up the 950 ft tower.
Ambulance and fire crews are on standby and police officers are inside the building.
The spokesman says their primary concern is the safety of the man.
He's believed to be Frenchman Mr Alain Robert who goes by the name of Spiderman.
He's already climbed many of the world's tallest buildings, including the Sears Tower in Chicago, the Empire State building in New York and the Petronas towers in Kuala Lumpur.
Scotland Yard confirmed that police, ambulance crews and the fire brigade are at the scene "monitoring" the actions of the man.
Mr Robert, 40, from Valence, who is married with three children, has scaled the Canary Wharf Tower before - in 1995.