The statement warned that traffic to the airport was "very congested" and facility's car parks were full.

Hong Kong airport authorities cancelled all remaining departing and arriving flights at the major travel hub on Monday after thousands of protesters entered the arrivals hall to stage a demonstration.

"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," the airport authority said in a statement.

The decision came after thousands of pro-democracy demonstrators flooded into the airport holding signs reading "Hong Kong is not safe" and "Shame on police".

"Airport operations at Hong Kong International Airport have been seriously disrupted as a result of the public assembly at the airport today," the statement said.

It warned that traffic to the airport was "very congested" and the facility's car parks were completely full.

"Members of the public are advised not to come to the airport."