Police on Tuesday said 15 Hongkongers between the ages of 12 and 15 had been arrested since anti-government protests erupted in June, with social workers calling for more access to the minors before and after detention. A 12-year-old protester, the youngest detained so far, was arrested on Sunday in Tsuen Wan after a police-approved march turned violent. Sources with knowledge of the case said the boy was arrested at around 6.45pm on Yeung Uk Road on suspicion of taking part in an unlawful assembly. He was taken to the Tsuen Wan police station about an hour later. He met with his father and a lawyer at 8.20pm. The boy later said his throat hurt and was taken to the Yan Chai Hospital in Tsuen Wan soon after midnight. He was released on bail on Monday afternoon and the Tsuen Wan District Crime Squad was assigned to investigate. The boy was expected to start his first year at a Chai Wan school next month. The school said in a statement that it has been in touch with the boy’s parents and was working on the case with the in-house social worker. The school said it had not disciplined the future student, contrary to claims on the internet. Senior Superintendent Steve Li Kwai-wah of the Organised Crime and Triad Bureau said in a Tuesday briefing that special protocols were followed when officers dealt with underage detainees. He cited as an example that parents were required to witness their child’s statements to officers. If parents were not available, an “appropriate adult” of the same gender would serve as a witness. When officers searched young people, an “appropriate adult” would also be present. “For the concerns or the protection of the youngsters, we have never allowed an adult inmate to be detained with the youngsters,” he said. But Jackie Chen Hung-sau, a social worker who was there when the boy was arrested, said police officers had initially bound his hands together with cable ties. By Chen’s accounts, it was only when she told the officers the boy was young that officers cut off the ties. Chen asked if she could accompany the boy to the police station but was refused. An officer was caught on camera saying: “How dare you call yourself a social worker... if you really care about the youngsters, don’t let them get out here [at illegal protests].” When the boy was detained, he shouted out his name and family members’ phone numbers. Chen was able to contact his parents and arranged a lawyer to help the boy at the Tsuen Wan police station. “The police are always saying that social workers are obstructing them from carrying out their duties,” she said. Chen said she hoped police officers would allow social workers help young detainees as the protest crisis continues. Labour Party lawmaker Fernando Cheung Chiu-hung, a social worker, said Hong Kong police guidelines state clearly that social workers come under the definition of “appropriate adult” and should be allowed to assist young detainees. “Those under the age of 16 are not as mature as adults. I hope [the Department of Justice] can show leniency and give them a chance,” said Cheung, who has asked that youngsters not be prosecuted. According to the University of Hong Kong’s Law and Technology Centre, there is a presumption under the common law by which a person under 14 years old was presumed not to have sufficient understanding of what is right or wrong. The centre said in its website that children of this age are incapable of forming the intent to commit a crime. To convict underage residents, the prosecution must rebut this presumption and prove the child in question knew that what he or she had done was wrong.