In a statement, the airport said the demonstrations had “seriously disrupted” airport operations, adding all check-in services for departing flights had been cancelled. Passengers have been advised to leave the terminal.

“Airport operations at Hong Kong International airport have been seriously disrupted, all flights have been cancelled,” read the statement. “All passengers are advised to leave the terminal buildings as soon as possible. Affected passengers please contact their respective airlines for flight arrangement.”

Any arrivals en route to Hong Kong will be allowed to land and disembark.

The situation is a further blow for the territory amid two months of mass demonstrations triggered by a controversial extradition bill.

The Foreign Office updated its Hong Kong travel advice on Monday, warning of several “large-scale political demonstrations”.

“Clashes have taken place between police and protesters following otherwise peaceful protest activities,” said the FCO. “These have involved significant violence. Reports indicate the protests are likely to continue.

“A protest at Hong Kong airport on 12 August has resulted in the cancellation of all flights out of Hong Kong for the remainder of 12 August.

“The airport authorities advise members of the public not to travel to the airport. Passengers should check their flight status on the Hong Kong International airport website.

“You should be prepared [for] the situation around protests and public gatherings [to] change quickly, with the potential for significant violence.

“If you are in and around areas where demonstrations are taking place, you should remain vigilant, follow the advice of local authorities and move away quickly to a safe place if there are signs of disorder.”