HONG KONG’S leader said yesterday that the city’s residents must “say no” to attempts to threaten China’s sovereignty after football supporters booed the national anthem the night before.

Chief Executive Carrie Lam, who was elected ealier this year, told the autonomous Legislative Council parliament that people living in Hong Kong are obliged to reject “any attempt to threaten our country's sovereignty, security and development interests.”

At an Asian Cup qualifying match between Hong Kong and Malaysia on Tuesday night, fans jeered and turned their backs to the pitch when the "March of the Volunteers" national anthem was played before the game.

Some held up a banner calling for Hong Kong independence in bold white lettering.

One supporter, Calvin Lau, told reporters the behaviour was "reasonable because Hong Kong people should be able to express their bad feeling or hate of China."

Recent weeks have seen growing portents of a repeat of the 2014 “umbrella revolution” student protests against Beijing’s bid to democratise the archaic Legislative Council, still elected by constituencies representing different business sectors. The council was set up during talks between the British and Chinese governments in the 1980s, before which the territory was ruled by a governor appointed by London and had no representative governing body.

Late last month Chris Patten, the last British governor of Hong Kong before the 1997 handover to China, urged citizens to defend their “freedom,” claiming Beijing was reneging on former leader Deng Xiaoping’s “one country, two systems” doctrine.

During a visit to Hong Kong earlier this year for Ms Lam's inauguration, Chinese President Xi Jinping said calls for separatism were a "red line” that should not be crossed.