A police officer was seriously injured by a lone assailant with a knife on a busy Hong Kong street on Thursday night as the city marked the 24th anniversary of its return to Chinese sovereignty. A video that captured the moment at around 10pm on July 1, 2021, has circulated widely online. Police said the uniformed officer was stabbed in the back outside the Sogo department store in Causeway Bay by a man who then used the knife on himself. Sources said the suspect was later certified dead at Ruttonjee Hospital in Wan Chai.