Floral tributes and a photograph of slain police officer Keith Palmer are seen outside the Houses of Parliament, two days after the March 22 Westminster terror attack in central London, Britain on March 24, 2017. (Xinhua/Han Yan)
Floral tributes and a photograph of slain police officer Keith Palmer are seen outside the Houses of Parliament, two days after the March 22 Westminster terror attack in central London, Britain on March 24, 2017. (Xinhua/Han Yan)