Sunday’s assault was blamed on criminals, but there are signs of links to pro-Beijing figures

At a pro-government rally on Saturday, one speaker made a disconcerting proposal for disciplining Hong Kong’s young protesters. “Do we have canes at home? Bring out your canes,” said Arthur Shek, a co-founder of the Economic Times newspaper. “Find a long one to beat your son. If you don’t have a cane, what do you do? We can still go to a hardware shop to buy a 20mm PVC pipe.”

The next day, dozens of men in white T-shirts and masks descended on a railway station in Yuen Long where they beat commuters with long bamboo rods and pipes.

Footage showed several men punching and kneeing demonstrators returning from an anti-government march. Photos showed commuters with bloodied faces and blood smeared on the station floor. At least 45 people were taken to hospital.

Shek has since apologised for his comment made in jest, but it is one of several details linking the attack to pro-government camps, at least in intention.

Protesters and opposition politicians have not only accused the government of looking the other way when the attacks took place – police arrived well after the assailants had left – but of facilitating them.

Galileo Cheng, 34, a Catholic church worker, was among those injured when he attempted to help a female journalist who was being beaten. He was taken to hospital and suffered bruises on his back and arms. An injury to his face may require plastic surgery.

Cheng said it was common knowledge that organised crime societies, or triads, were active in areas such as Yuen Long in the outskirts of Hong Kong.

“Normally, they won’t attack local citizens,” he said. “Utilising triads to assault citizens, threatening them to withdraw from the social movement, is a common tactic used by the Communist party, qunzhong dou qunzhong” – ‘the masses fighting the masses’. It seems the government has no way to stop the protests.”

A video showed the pro-Beijing legislator Junius Ho meeting the men in white in Yuen Long, shaking their hands, and giving them a thumbs-up. When one praised Ho, he responded: “You are all my heroes.”

In response to accusations that he had hired the men to go after protesters, Ho said in a press briefing on Monday that he had nothing to do with the attack and only warned residents to be safe and avoid violent protesters.

When a journalist pointed out that the men had attacked protesters first, he said: “I don’t know what happened. I can’t criticise it, but … hitting people is wrong. It’s as simple as that.”

Hong Kong’s chief executive, Carrie Lam, and the police chief have vehemently denied any connection with the attack, calling such accusations “insulting”.

Sunday’s violence in some ways mirrors similar attacks in 2014 during Hong Kong’s pro-democracy Umbrella movement. After demonstrators occupied the city centre for weeks, men with mainland Chinese accents began assaulting protesters. Now that the latest protests are in their seventh week, officials may again be desperate to put them down.

“This is not the first time thugs have been sent in to beat up protesters,” said Lynette Ong, a political scientist at the University of Toronto who has been studying organised crime in China. “This is more organised, suggesting they are becoming more daring, and the Hong Kong government or pro-Beijing officials are becoming more desperate to put the protests to rest.”

The method has precedent in mainland China, where local authorities are known to hire thugs to intimidate residents unwilling to give up their land, or to silence troublesome petitioners.

“The underlying motive is quite similar … Sending in thugs is an option to evade responsibility,” said Ong. “If you send thugs, it’s almost impossible to trace, and you can’t hold anyone accountable.”

Unlike the attacks in 2014, the assailants appeared to be from Hong Kong, cursing fluently in Cantonese, according to Cheng.

The triads, who enjoy privileges related to their clans in their respective areas, may not necessarily have been paid or ordered to attack commuters and protesters.

“These thugs … terrorise the protesters so fewer people will come out to protest,” said the pro-democracy legislator Ray Chan. “Some opportunists among them may even want to get political credit for their actions, so they will be in a better position to demand more influence in government policies that favour them,” he said.

The attacks may not have served their intended purpose. Demonstrators have been called on fellow protesters to “prepare to fight” and some are planning to apply for a permit to hold the next rally in Yuen Long.