The police chief yesterday defended officers who used pepper spray recently during a clash with protesters outside the Legislative Council, saying it was used in accordance with strict rules. Officers in riot gear used the pepper spray to subdue hundreds of demonstrators - angry after government funding was approved for the HK$66.9 billion high-speed railway to Guangzhou - outside the Legco building on January 16. Police Commissioner Tang King-shing was responding on-air to criticism from callers to an RTHK radio show yesterday, who condemned police for not respecting people's rights. They said police should not have used violence. One caller said: 'Do the police have guidelines for the use of pepper spray? The protesters did not attack police. It was unacceptable to use pepper spray on the protesters.' Tang responded: 'We act in accordance with our rules and the situation when police use any violence. If any police officer uses violence, they need to be responsible for their actions. Police have had training. They know how to respond to different situations.' Tang said police would improve communication with young protesters to try to ensure rallies are staged lawfully. 'It is important for us to enhance communication with young people, to understand their thoughts,' he said. 'The government respects freedom of assembly and speech. The police's duty is to ensure public safety and public order.' One caller said it was inappropriate for police to use cameras to record footage of the demonstration. Tang said the recordings would be used as evidence and that police did not film individuals. Separately, when asked about the niece of a Court of Final Appeal judge, Mr Justice Kemal Bokhary, Tang said she had been detained in the interest of public safety. The woman was arrested for slapping a policeman and refusing to take a breath test after her car collided head-on with a tour bus in Happy Valley on January 27.