More details emerged on Sunday of how undercover police officers fired two warning shots in the air at Victoria Park on Saturday night after being uncovered by extradition bill protesters who then attacked them and tried to grab one of their guns. The live rounds were fired skywards and there were no reports of injuries, said a spokeswoman, who emphasised the officers had clearly indicated they were police and given clear warnings after being attacked by a crowd. But critics objected to the officers disguising themselves as protesters, who usually wear black clothes with helmets and face masks, and accused the police of allegedly using excessive force in firing the deadly weapons. It was the second time live rounds were fired during 13 weeks of protests against the now-shelved extradition bill, but the first time a firearm was used by police operating undercover as protesters, a police spokeswoman confirmed at a press conference early on Sunday morning. The rounds were fired at 9.05pm and 9.10pm respectively at Victoria Park in Causeway Bay during a night of chaos and violence with multiple clashes in several neighbourhoods between anti-government protesters and police officers following a banned rally on the Hong Kong Island. Police arrest 63 after chaos on Hong Kong’s train network Earlier in the day, police had fired blue dye from water cannons, multiple rounds of tear gas and used pepper spray on protesters, who had lit fires and hurled petrol bombs. Amid the chaos one protester alerted others on Great George Street that there were undercover police in nearby Victoria Park, identifiable by flashing LED lights on their backpacks, according to a witness at the scene interviewed by local media. A group of protesters surrounded another group of men dressed in black, one of whom broke free and ran towards the harbourfront, according to an anonymous eyewitness. Other protesters gave chase and managed to catch him and pin him to the ground, remove his mask and take his mobile phone, the eyewitness said. Police deny planting evidence and say protesters dropped sticks during course of arrest According to the police spokeswoman, the undercover officers were being surrounded, taunted and attacked by protesters, who tried to snatch their mobile phones and one officer’s firearm. One live round was fired in the air at around 9.05pm, she said. The officers then retreated further into Victoria Park as at least 10 protesters attacked them with metal poles, bamboo sticks, bricks and petrol bombs. A second warning shot was fired in the air at 9.10pm near a fountain in Victoria Park. Video from other local media showed a man dressed as a protester pointing a pistol at another black-clad man, and then arresting him. Elite police ‘raptor’ squad went undercover to target radical protesters, insiders say Several other protesters were also seen being handcuffed by undercover officers in a separate video filmed by local media. The police have yet to confirm if anyone had been arrested in Victoria Park following the incident. Undercover officers were first spotted on August 11, also in Causeway Bay, when police dressed in black arrested protesters on the street, a move protesters later said had caused them to lose trust in their peers. Police have argued that undercover officers have to be part of their operations to be able to deal with violent protesters and their actions were within international norms.