Activists plan to converge on the airport on Friday afternoon, with more protests planned across the city at the weekend. On July 26, thousands of black-clad protesters occupied the airport's arrival area to stage a massive sit-in against the government's handling of the now-suspended extradition bill, inconveniencing travellers.

"To maintain the smooth process of the departure procedures of passengers and the terminal operation, only departure passengers with an air ticket or boarding pass for the next 24 hours and a valid travel document, or airport staff with identity proofs will be allowed to enter to the check-in aisles at Terminal 1," the Airport Authority said in a statement.

HKIA, one of the world's busiest aviation hubs, handled about 7.5 million passenger trips in 2018 and offers transit shuttles to more than 110 mainland cities, according to the airport's latest report.

The government on Thursday said tourist arrivals dropped 26% at the end of last month compared to last year and were continuing to fall in August. The travel industry accounts for 4.5% of the financial hub's economy and employs about 2500,000 people, or about 7% of the total working population.