Queen Elizabeth has sent her condolences to those affected by the attack on the British parliament conducted by a lone assailant who killed three people and injured 40.
"My thoughts, prayers, and deepest sympathy are with all those who have been affected by yesterday's awful violence," she said in a statement.
The Queen was due to officially open the new headquarters of London's police force on Thursday but will now do so at a later date.
It's expected that police will be involved with a major investigation into Wednesday's attack that will occupy many officers at Scotland Yard.
The Queen was to have been joined by her husband Prince Philip at the official opening of the new building.
