The violence followed a Sunday afternoon rally through the centre of the New Territories town attended by tens of thousands.

“The mob lost the run of themselves, and their behaviour was horrendous,” Lo said early on Monday.

But lawmakers and district councils accused the force of deploying the wrong tactics by entering the shopping centre and clearing the site, saying most protesters were trying to leave Sha Tin through the MTR station in New Town Plaza, but were initially blocked by police.

As they moved towards the station, riot police came from behind triggering a violent reaction from protesters.

Pitched battles on Hong Kong streets and inside malls after protest

Asked about the force’s approach, Lo said: “When there are people breaking the law, should police really just allow them to do so? Police were working very hard, but their diligence has only been greeted with accusations.”

On Monday morning, the Hospital Authority said a total of 28 people were injured after Sunday night’s clashes between police and protesters, with 22 admitted to hospital, including two in critical condition. Four were in serious condition and 14 stable.

Meanwhile, police said at least 10 officers were injured, including one who lost a finger.

Former secretary for transport and housing Anthony Cheung Bing-leung said police should not be put in the middle between the government and protesters, as he urged city leaders to find a political solution to relieve pressure on the force.

Cheung told a radio programme the extradition bill controversy was a political issue that police had no role in resolving. As the government’s representative on the streets and the guardians of public order, they had become a target for protester anger, he said.

The march in Sha Tin drew 115,000 people, according to organisers. Police said 28,000 attended at the rally’s peak.

Events took a darker turn with scuffles breaking out at about 5pm before a stand-off lasting several hours on the streets of Sha Tin.

Police made attempts to clear a large crowd at the intersection of Yuen Wo Road and Sha Tin Rural Committee Road. Officers closed in on the crowd soon after 9pm with protesters seen leaving through Sha Tin Centre shopping mall, although others remained.

In disturbing scenes played out across three shopping centres, officers were surrounded and attacked by groups of young demonstrators wearing masks and helmets, while protesters were also beaten and pepper-sprayed.

Police officers can enter and search any premises without a warrant, if they have reason to believe a person to be arrested is inside, according to the Community Legal Information Centre of the University of Hong Kong.

Thirteen Sha Tin district councillors met the press at New Town Plaza, where some of the most chaotic scenes were centred, after the trouble ended at about 11pm on Sunday.

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“As to what happened, we as a group of district councillors feel very, very shocked and very, very angry,” Wai Hing-cheung said.

He questioned why police entered New Town Plaza, a private venue, without the owner’s approval.

“I wouldn’t say there was much vandalism taking place, but police used violence against citizens anyway,” Wai said, adding that he could not understand the reason for such action.

Representatives from Sun Hung Kai Properties, owner of the mall, said they did not report the matter to police nor did they receive any notification from officers about entering the property.

On Monday morning, the plaza had largely returned to normal with little trace of the violence witnessed just hours earlier, as residents were seen going to work through the MTR station as usual.

Hong Kong protesters showered with support – even from 10 floors up

Selina Tsang, who recently retired, went to the Sha Tin rally with her friends and their children, who are aged about 10.

After hearing about violence breaking out, she headed home to Ma On Shan through Tai Wai station at around 6pm.

She questioned why police would block the exits and prevent people from leaving if they really wanted them to disperse.

“Although I don’t support violence, the current situation has been forced on protesters and is not out of choice,” Tsang said. “I understand police have their duties, but those on the front line also have a responsibility to think independently.

“Although they have to act according to the rules, they must consider their actions carefully before taking unreasonable action like beating people.”

But resident Sheung Hau, 82, and his wife Mrs Hau, 76, saw it differently.

“It’s weird. If the protesters really want to protest peacefully, why would some – it might be a small number – be armed and bring weapons?” said Mrs Hau, who did not give her full name.

“I think both sides [police and protesters] are not showing enough restraint. They both did wrong. Both sides are Hongkongers and we Hongkongers don’t want to see a chaotic society,” she said.

Clothes shop employee Miss Cheung was at work on Sunday and said she heard the sound of clashes between police and protesters at about 6pm.

She said the shop, on the upper ground floor, had fewer customers than normal over the past two days because of the protest, and on Sunday had to close at 9pm, an hour earlier than the usual.

“We were not sure what exactly was going on,” Cheung said on Monday. “But if protesters were only shouting slogans or suchlike, then police actions were too much.”

Mrs Ho, an employee at another clothes shop on the same floor, said customer flow has dropped significantly. The shop owner had told them to close at 3pm on Sunday.

She believed “police were doing the right thing to enforce the law. If protesters mess around, police should perform their duties”.

Ho said the protest had left residents in no mood to shop: “They walked by the shop, saying they did not want to buy clothes and that they just wanted to go home.”