LONDON — British police say they have arrested and used a stun gun on a man armed with two knives outside Buckingham Palace.

Scotland Yard said the man, thought to be in his 50s, acted aggressively when challenged by police outside the gates of the heavily touristed landmark on Sunday. Officers used a Taser gun on him and took him to a London police station.

The man was not named and police did not provide details of his identity.

Parts of the area outside the palace gates, usually crowded with tourists, were cordoned off. No injuries were reported.

Queen Elizabeth II and her husband Prince Philip were at their country retreat, Sandringham Estate, on Sunday. The palace declined to comment on the incident.