Anti-government
protests that have roiled Hong Kong for more than three months spread to the sports field on Tuesday, as many local fans defied Chinese law to boo the country's national anthem ahead of a soccer
World Cup qualifier against Iran.
Earlier on Tuesday, the city's Beijing-backed leader, Carrie Lam, warned against foreign interference in Hong Kong's affairs, adding that an escalation of violence could not solve social issues in the Asian financial hub.
Hong Kong returned to Chinese rule in 1997 under a "one country, two systems" formula that guarantees freedoms not enjoyed on the mainland.