Queen Elizabeth II will no longer visit the New Scotland Yard tomorrow.
The royal's engagement to open the Metropolitan Police's new headquarters in Scotland Yard on Thursday has been postponed following a an attack that took place outside the U.K. Parliament on Wednesday.
Royal reporter Richard Palmer tweeted, "Buckingham Palace: 'In light of today's events the decision has been taken to postpone the Queen's engagement to New Scotland Yard. tomorrow. The visit will be rearranged for a later date.'"
According to The Telegraph, four people were killed and 20 injured after a car and knife attack outside the U.K. Parliament Wednesday afternoon, which the Scotland Yard police are calling a "terrorist incident."
Witnesses told the publication that the attacker, armed with two large knives, ran over pedestrians with his car on Westminster Bridge before rushing the gates in front of the Houses of Parliament and stabbing a policeman. He was eventually shot dead by armed officers on the premises.
Prime Minister Theresa May described the attack as "sick and depraved" and thanked the "exceptional men and women" of the police force who responded to the attack.
"We will all move forward together, never giving in to terror and never allowing the voices of hate and evil to drive us apart," she promised.
At the time of the attacks, the Queen was at Buckingham Palace while Prince Charles was in Yorkshire, northeastern England, carrying out a variety of visits.
Though Prince William, Kate Middleton and Prince Harry were not carrying out any public affairs Wednesday, the Duchess of Cambridge has a scheduled engagement in London on Thursday as part of their Heads Together campaign.