People around the world have been showing support, after the serious attack in Westminster in London on Wednesday.
Prime Minister Theresa May led tributes to the emergency services and members of the public who looked after people during the attack outside Parliament on Wednesday. She said that the attack would not stop London from carrying on as normal - "We will all move forward together."
Flags including this one over the Houses of Parliament were flown at half mast as a sign of respect for the people who were killed or injured in the attack.
Metropolitan Police/PA Wire
Scotland Yard, which is the headquarters of the police service in London also flew its flag at half mast, after the death of police officer Keith Palmer.
London Mayor Sadiq Khan said that the people of London would not be intimidated by terrorism.
This message about having hope in difficult times was left at the Tower Hill tube station in London.
And flowers were left on Westminster bridge, and on the pavement close to St Thomas' Hospital where some of the victims were taken for treatment.
The Library of Birmingham was lit up with the colours of the Union Flag.
Library of Birmingham
Elsewhere, leaders from around the world sent messages of support. German Chancellor Angela Merkel said that her thoughts were "with our British friends and all of the people of London".
France's President Hollande said that French people understand the suffering of those involved, because of similar attacks that have happened recently in France.
And the lights were turned out on the Eiffel Tower in Paris to show France's support for London.
US President Trump said that he had spoken to Prime Minister Theresa May to offer condolences after the attack. He said "She is strong and doing very well".
In India, this artist made a sand sculpture saying "Stop terrorism".
And Israel showed support as well, lighting up the City hall in Tel Aviv to look like the Union Jack.