As of 12 noon on 5 August, Cathay Pacific and units Cathay Dragon and HK Express have cancelled more than 150 flights in and out of the city on 5 August. These were flights to various points across Asia.
Meanwhile, Hong Kong Airlines has cancelled more than 30 flights in and out of Hong Kong International Airport on 5 and 6 August. These include points such as Bangkok, Shanghai Pudong and Tokyo Narita.
It was not just Hong Kong carriers that suspended flights. China Airlines and subsidiary Mandarin Airlines, which have flights to Hong Kong from points such as Taipei Taoyuan, Kaohsiung and Jakarta, have also suspended some flights to Hong Kong. Fellow Taiwanese carrier EVA Air has also pulled flights to and from the city.
In a notice on its website, Hong Kong International Airport says "potential circumstances" on 5 August might affect flight operations. It advised passengers to check with their airlines for the latest flight information.
The South China Morning Post reported that Hong Kong International Airport could only have one of its two runways operational between 5 and 6 August, as result of the strikes.
The disruptions to flight services come as air traffic controllers went on strike, as part of the anti-government protests.
Hong Kong has been rocked by protests for the past two months, over the government's decision to introduce an unpopular extradition bill. It was later shelved, but protesters have demanded the full withdrawal of the bill and an investigation into the way the political crisis has been handled.