"All passengers are advised to leave the terminal buildings as soon as possible", a statement from the Airport Authority said.
In a statement on Monday, Hong Kong's Airport Authority said they were cancelling all flights that were not yet checked in.
The bill received widespread backlash when the government tried to rush its amendments through the legislature in June, amid fears that the changes would make those passing through Hong Kong vulnerable to extradition and trial in China's courts-notorious for the absence of rule of law.
Earlier Monday, Hong Kong police showed off water cannons that could be deployed in the case of future demonstrations, a development which Amnesty International has warned could lead to serious injuries if the canons are misused within the densely-populated city's confined spaces. Unconfirmed reports that she had potentially lost an eye were circulating Monday, with calls for an "evil police eye for an eye" protests to be held in response, with the airport as the primary target.
Many of those protesting are critical of the actions of police, who on Sunday were caught on film firing tear gas and non-lethal ammunition at close range.
Eleven-year-old Janice Ly and her mother, Ping Fam, from Surrey, B.C., were scheduled to be on the only flight to Canada that was cancelled during the mass pro-democracy protests. A San Francisco flight landed in Hong Kong earlier Monday with no issues, Gibbs said.
Chinese troops last week amassed at the Hong Kong border, sparking concerns Beijing could enact martial law, leading to a citywide strike that ended up in the cancellation of more than 200 flights.
By appealing to the global community, and making sure it is their message that most foreigners are seeing, protesters have shown themselves adept at public relations.
Beijing has pointed to Washington figures such as Vice President Mike Pence, Secretary of State Mike Pompeo and White House national security adviser John Bolton meeting Hong Kong opposition supporters and the presence of US flags at rallies as evidence of foreign interference.
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The government has said it will not negotiate with the separatists until they hand over all the military positions they seized. The commander was among 36 people killed - many of them newly graduated cadets - in the aerial attack, claimed by the Houthis.
North Korea said late on Sunday it fully supports China on the situation in Hong Kong, which it also said was caused by "foreign forces" interfering in an internal affairs of China to encroach on the security and order of the Chinese city.
Hong Kong leader Carrie Lam has refused to yield to a series of demands, including that she withdraw the bill and step down from her position.
The local police adopted a more aggressive approach to deal with the protests in the last few days, such as chasing after fleeing protesters in a claustrophobic subway corridor and ambushing demonstrators while disguising themselves as protesters.
Protesters use traffic cones to cover the tear gas canisters fired by riot police.
The Beijing regime has strongly hinted several times that it could use the Chinese military to suppress the protests.
Hong Kong, a former British colony, was returned to China in 1997 under the framework of "one country, two systems".
The Hong Kong administration branded the protests as "unlawful assemblies" and said a petrol bomb had injured a policeman.
Outside in the streets of Hong Kong, crowds picketed a police station, singing hymns.
The pilot has been suspended, and the airline has also fired two ground staff, reportedly after they leaked information on a Hong Kong police football team that was travelling to the mainland. In Hong Kong she doesn't relate to what the Hong Kong people are protesting for.