An alarm prevailed on Thursday afternoon at Buckingham Palace, when an unknown man surprised security and handcuffed himself to the bars at the main gate.

Footage on social media showed a man in his 30s, dressed in a white T-shirt and black trousers, at the gates of the palace as hundreds of tourists gathered to view the iconic building.

The policemen they quickly cordoned off the area and they appeared to be trying to reason with the stranger.

Emergency services rushed to assist the police officers who are already at the scene.