“It feels great [to watch]! Kill them all, these trash and tumours of society,” a Weibo user replied to the video, with a thumbs-up emoji.

“Hongkong’s loser youth, [police] should totally open fire!! It would be best to shoot them in the head,” another post read.

These comments, and many others like them flooding social media in mainland China, highlight the deep divisions in views on each side of the border as Hong Kong’s political crisis drags into its sixth month.

Despite some initial sympathy, mainland public sentiment towards Hong Kong has hardened since July, amid state propaganda painting the protesters as a separatist movement plotted by “Western black hands”.

In recent weeks, the rancour from the mainland has only appeared to deepen, with photos and videos of protesters vandalising businesses with ties to the mainland spreading online.

Last month, a mainland Chinese banker was assaulted in a confrontation with protesters during his lunch break in Central, drawing the wrath of many mainlanders and renewed online calls for military intervention.

Extensive media coverage of the vandalism and attack, as well as a series of inflammatory commentaries, have further fanned the anger.

On Monday, the social media account of state-run Beijing Daily ran the story of the shooting under the headline: “This morning, a gunshot in Hong Kong, to the applause of citizens!”

“At such a critical moment, the police officer acted so bravely and restrained,” the report said.

“After the police fired the shot and subdued the rioters, some citizens at the scene directly applauded the police. The reaction of the public directly shows that the officer fired not only in a legal and reasonable way, but also in line with the will of the people.”

In the video, a man in a dark blue jumper claps his hands at a nearby traffic light, as police officers pin the protesters to the ground.

A report in Beijing Daily did not mention that angry bystanders condemned the officers as “murderers”.

Hong Kong police officer who shot protester receives death threats against children

Hu Xijin, editor-in-chief of nationalist tabloid Global Times, and a regular – and hugely popular – commentator on Hong Kong’s unrest, also weighed in.

“As a media worker, I resolutely support this Hong Kong police officer gunning down the attacking rioters,” he wrote to his 2 million fans on Weibo in a post that included video of the shooting.

Hu accused Hong Kong and Western media of “focusing their coverage on the police shooting and diluting the illegal, criminal and evil deeds of the rioters”.

“Such guiding of public opinion is disgusting,” he wrote.

Hu ended his post with a message to Hong Kong police: “Don’t you be afraid of anything, resolutely defend Hong Kong’s law and order, be strong and be tough. You’re not alone on the front lines.

“Behind you there are not only the [patriotic] Hong Kong public and the nation, but also the country’s paramilitary police and the People's Liberation Army Hong Kong garrison, who can enter Hong Kong and offer support in accordance with the Basic Law when needed.”

The post was liked more than 26,000 times in six hours.

Scores of Chinese students flee Hong Kong over fears they will be attacked

Meanwhile, Taiwanese President Tsai Ing-wen called on the Hong Kong government to give a detailed response to the Hong Kong people’s calls for democracy and freedom, which she described as “the only path to return to stability and order”.

“Governments should not fire upon unarmed people, this will only exacerbate the problem,” she wrote on her official Facebook account. “Beijing and the Hong Kong government should respond to the Hong Kong people, not with bullets but with the promise of democracy and freedom.”

Taipei’s Mainland Affairs Council, which oversees the island’s policies on Beijing, called on all sides to give up their arms and aggressive actions to make way for peaceful conversation.