HONG KONG—Hong Kong will ban all passenger flights from the United Kingdom from Thursday to curb the spread of the Delta variant of COVID-19, the government said on Monday. Britain will be specified as extremely high-risk, and people who have stayed in the country for more than two hours will be unable to board passenger flights bound for Hong Kong, it said. It is the second time Hong Kong has barred arrivals from Britain after a ban that was in force from December 2020 until May. The government said the ban was due to “the recent rebound of the epidemic situation in the UK and the widespread Delta variant virus strain there, coupled with a number of cases with L452R mutant virus strains detected by tests from people arriving from the UK.” Parents in Hong Kong with children in Britain reacted with shock. They complained that they had paid large …