A man has been arrested after trying to get into Buckingham Palace with a knife, Scotland Yard said.
The 44-year-old was held at around 11.30am when he attempted to get through the north centre gate and was stopped by police.
Officers searched him and he was found to have a knife.
He was arrested on suspicion of trespassing on a protected site and possession of an offensive weapon and is in custody.
Buckingham Palace said that the Queen was not in the building when the man tried to get in, but would make no further comment.