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."
Meanwhile, China on Monday slammed violent protesters in Hong Kong who had thrown petrol bombs at police officers and linked them to "terrorism," as Beijing ramps up its rhetoric against pro-democracy protests in the financial hub.
"Hong Kong's radical demonstrators have repeatedly used extremely dangerous tools to attack police officers, which already constitutes a serious violent crime, and also shows the first signs of terrorism emerging," said Yang Guang, spokesman for the Hong Kong and Macao Affairs Office of the State Council.
"This wantonly tramples on Hong Kong's rule of law and social order," he said at a press briefing in Beijing.
Hong Kong police on Monday unveiled water cannon trucks as a new way to combat pro-democracy protesters, after tear gas and rubber bullets failed to stop more than two months of rallies.
The brand-new vehicles, complete with real-time surveillance cameras and multiple spray nozzles, were wheeled out after police clashed with demonstrators at nearly a dozen locations on Sunday.
They fired tear gas on shopping streets and in subway stations, with protesters hurling bricks and spraying riot police with fire extinguishers and water hoses.
A government official said 45 people were injured in the clashes, including two who were in serious condition.
Among them was a woman who suffered a serious face injury, reportedly after being hit by a bean bag round, with rumors circulating that she had lost her vision in the incident.
Images of her lying on the ground with blood pouring from her face quickly went viral and featured on posters calling for new demonstrations.
"An eye for an eye" read one call for a protest on Monday afternoon at the city's airport, where thousands of protesters dressed in their movement's signature black gathered holding signs reading "Hong Kong is not safe" and "Shame on police."
Police have defended themselves as accusations of using excessive force against protesters and on Monday unveiled two water cannons -- a method that has not yet been used during the crisis.
They demonstrated jets of water from the trucks on several dummy torsos placed at different distances from the vehicles.
Hong Kong has reportedly ordered three of the vehicles at a cost of HK$27 million ($3.4 million), though police declined to confirm the exact price-tag.
Police would only use the trucks in the event of a "large-scale public disturbance" leading to "casualties, property being destroyed wantonly, or public order and public safety coming under grave threat", senior superintendent Chan Kin-kwok told lawmakers.
The vehicles are "one of our options for our use of force or special tactics," he added during the Monday presentation.
Pro-democracy lawmakers attended the presentation holding signs that read "HK Police Murderers" and quarreled with pro-Beijing lawmakers, who praised the police for their response to the demonstrations.
"We saw recently that the police's control of their emotions is extremely poor," said Lam Cheuk-ting, who accused police of having "abused their power to attack many protesters who aren't resisting".
It was the tenth consecutive weekend that protesters have taken to the streets in a movement that began over opposition to a bill allowing extradition to mainland China.
The protests have morphed into a broader bid to reverse a slide of democratic freedoms in the southern Chinese city.
They have been seen as the biggest threat to Beijing's rule since Britain handed Hong Kong over in 1997.