Hong Kong airport authority on Monday suspended all remaining flights for the day after thousands of pro-democracy protesters entered the terminal's arrival halls.
The authority said that they were suspending departing and arriving flights in the wake of the sit-in demonstration, Al Jazeera reported.
"Other than the departure flights that have completed the check-in process and the arrival flights that are already heading to Hong Kong, all other flights have been cancelled for the rest of today," it said in a statement.
Traffic on roads to the airport was very congested and car park spaces were full, the authority said.
Increasingly restive protests for over two months have plunged Hong Kong into its most serious political crisis in decades.
The protests, which started over a controversial extradition bill, expanded into wider calls for democratic reforms and an independent inquiry into police conduct during the demonstrations.
The protestors' demands include the resignation of pro-China Chief Executive of Hong Kong, Carrie Lam, and an election for her successor.