Chinese officials condemned protesters in Hong Kong as no different to “terrorists” on Wednesday, a further hardening of the state’s rhetoric amid fears that the country is readying the ground for a military intervention.

After 10 weeks of clashes between protesters and police that threaten the city’s status as a safe transport and international finance hub, Chinese state media also called for a more decisive response from Beijing.

It comes as videos showed Chinese forces assembling for “apparent large-scale exercises” near the border between the mainland and the semi-autonomous city. Donald Trump accused the Chinese government of building up troops and urged calm.

But in its strongest statement yet on the protests, the Chinese cabinet’s liaison office with Hong Kong said the protesters had “entirely ruptured legal and moral bottom lines” and would face swift and severe repercussions under Hong Kong’s legal system.

Xu Luying, spokesperson for the Hong Kong and Macau Affairs Office, said the clashes in Hong Kong airport on Monday and Tuesday, which saw five protesters arrested, had “seriously tarnished Hong Kong’s international image”.

Continuing protests rock Hong Kong: In pictures Show all 35 1 /35 Continuing protests rock Hong Kong: In pictures Continuing protests rock Hong Kong: In pictures Police officers point their guns towards pro-democracy protesters after a clash at a march in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Pro-democracy protesters throw molotov cocktails during clashes with riot police in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Demonstrators rally behind barricades ass they are shrouded in tear gas deployed by police in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Police clash withpro-democracy protesters at a march in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures A police officer prepares to strike a protester as clashes erupt during a pro-democracy march in Hong Kong on August 24 AFP/Getty Continuing protests rock Hong Kong: In pictures A water cannon is fired by riot police to clear the street of demonstrators during a protest in Hong Kong on August 25 EPA Continuing protests rock Hong Kong: In pictures Pro-democracy protesters use a slingshot during clashes with riot police in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Riot police fire tear gas to disperse pro-democracy protesters in Hong Kong on August 24 Reuters Continuing protests rock Hong Kong: In pictures A demonstrator throws a molotov cocktail as they clash with riot police during a protest in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures A demonstrator swings a tennis racket in an attempt to knock back a tear gas cannister thrown by riot police during a protest in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures A protester displays a Hong Kong Independence flag during a pro-democracy march in Hong Kong on August 24 EPA Continuing protests rock Hong Kong: In pictures Riot police tend to a detained demonstrator who has been injured during a protest in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures A demonstrator uses bamboo poles to build a barricade during a protest in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Riot police clash with demonstrators during a protest in Hong Kong on August 24 Reuters Continuing protests rock Hong Kong: In pictures Protesters are hit by tear gas fired by the police in Hong Kong on August 24 AFP/Getty Continuing protests rock Hong Kong: In pictures Demonstrators shrouded in tear gas shield themselves behind barricades during a clash with riot police in Hong Kong on August 25 Getty Continuing protests rock Hong Kong: In pictures Riot police arrest a protester during a pro-democracy march in Hong Kong on August 24 EPA Continuing protests rock Hong Kong: In pictures Police clash with pro-democracy protesters at the Hong Kong international airport on August 13 AFP/Getty Continuing protests rock Hong Kong: In pictures Protesters fall back as they clash with police during a protest at Kowloon Bay in Hong Kong on August 24 AFP/Getty Continuing protests rock Hong Kong: In pictures Police clash with pro-democracy protesters at the Hong Kong international airport on August 13 Reuters Continuing protests rock Hong Kong: In pictures Riot police move to disperse protesters during a clash at the Hong Kong international airport on August 13 Reuters Continuing protests rock Hong Kong: In pictures Commuters riding in a bus drive past protesters in Hong Kong's Kowloon Bay on August 24 AFP/Getty Continuing protests rock Hong Kong: In pictures Protester hold umbrellas as they take part in a pro-democracy march in Hong Kong on August 24 EPA Continuing protests rock Hong Kong: In pictures Riot police detain a demonstrator as they clash during a protest in Hong Kong on August 24 Reuters Continuing protests rock Hong Kong: In pictures Pro-democracy protesters block the entrance to the airport terminals after clashes with police at the Hong Kong international airport on August 13 AFP/Getty Continuing protests rock Hong Kong: In pictures Riot police spray pepper spray as shield themselves by a police van during a clash with pro-democracy protesters at the Hong Kong international airport on August 13 Reuters Continuing protests rock Hong Kong: In pictures Riot police use pepper spray to disperse protesters during a demonstration at the Hong Kong international airport on August 13 Reuters Continuing protests rock Hong Kong: In pictures Demonstrators shrouded in tear gas shield themselves behind barricades during a clash with riot police in Hong Kong on August 25 Reuters Continuing protests rock Hong Kong: In pictures Medical professionals gather to protest police brutality at the Queen Elizabeth Hospital in Hong Kong on August 13 Getty Images Continuing protests rock Hong Kong: In pictures Police detain a pro-democracy protester at the Hong Kong international airport on August 13 AFP/Getty Continuing protests rock Hong Kong: In pictures A protester is halted by police during an occupation at the Hong Kong international airport on August 13 AP Continuing protests rock Hong Kong: In pictures Police clash with pro-democracy protesters at the Hong Kong international airport on August 13 AFP/Getty Continuing protests rock Hong Kong: In pictures Police stand guard at the entrance of the departure terminals at the Hong Kong international airport on August 13 AFP/Getty Continuing protests rock Hong Kong: In pictures Protesters continue their occupation at the Hong Kong international airport on August 14 AP Continuing protests rock Hong Kong: In pictures Travellers read placards and posters left by pro-democracy protesters at the Hong Kong international airport on August 14 AP

She called assaults on two mainland Chinese men, one of whom has been identified as a reporter for the state-run Global Times tabloid newspaper, as “nearly acts of terrorism”.

A front-page commentary on the overseas edition of the Communist Party’s official People’s Daily newspaper said Hong Kong had reached a critical juncture.

“Using the sword of the law to stop violence and restore order is overwhelmingly the most important and urgent task for Hong Kong!” it said.

Another commentary published in China Daily, written by Shenzhen University researcher Li Peiwen, suggested that “extreme political ideas” had taken root in Hong Kong and that the central government should deal with the situation more decisively.

However, Chinese state media have still stopped short of calling for military action to deal with the protests. China’s People’s Liberation Army (PLA) has a garrison in Hong Kong, but troops have remained in barracks since the protests started in April.

Meanwhile, flights resumed at Hong Kong’s airports on Wednesday as statements were displayed from some protest leaders, regretting the clashes with riot police and asking international travellers “for your understanding and forgiveness as young people in Hong Kong continue to fight for freedom and democracy”.

The airport increased security measures and said it had obtained an injunction to prevent protesters from entering the premises and “unlawfully and wilfully obstructing or interfering” with operations.

An area outside the main terminal had been set aside for demonstrations, management said, adding that no protests would be allowed outside the designated area.

Hong Kong’s flag carrier Cathay Pacific, facing pressure to act from Beijing, said in a statement that it had sacked two pilots who were previously suspended, one for involvement in last month’s clashes, the other for “misusing company information” in relation to the protests.

Where once the Hong Kong protests appeared to be a taboo subject for newsrooms in mainland China, the issue is now dominating TV bulletins.

On Wednesday, state broadcaster CCTV showed interviews with stranded travellers at Hong Kong airport. One flight data company said long-haul bookings to Hong Kong were down almost 5 per cent compared to this period last year.

CCTV has started regularly airing interviews with pro-police demonstrators, according to Reuters, and on Monday it said a female protester had been blinded by fellow demonstrators. There have in fact been conflicting claims over how she was injured during the clashes.

State-run media have been posting messages online describing the city’s crisis as “a shame”. On Weibo, the People’s Daily wrote a post saying “We support the Hong Kong police too!” – it was shared more than 500,000 times.

Many reactions online are speculating about what China will do next, after Hong Kong’s chief executive Carrie Lam again refused to stand down or begin dialogue with the protest movement, accusing them of threatening to push their home into an “abyss”.

Some netizens in China’s social media platforms called for Beijing to intervene. Many others, however, have urged calm.