HONG KONG (Reuters) - Hong Kong police on Tuesday detained three people under the city’s contentious national security law on suspicion of publishing content to incite others to secede from China.Police said two men and a woman, aged between 17 and 21, were in custody and an investigation was under way. Authorities did not name the suspects but pro-independence group Studentlocalism said three of its members, including Tony Chung, a former leader of the organisation, were among them. The former British colony of Hong Kong returned to Chinese rule in 1997 and has been rocked by pro-democracy demonstrations in recent years. Beijing imposed a national security law on its freest city on June 30, a move widely condemned by Western governments and human rights groups. The law punishes what Beijing broadly defines as secession, subversion, terrorism and collusion with foreign forces with up to life in prison. Chung was taken away from a coffee shop close to the U.S. consulate by unidentified men, local media reported, adding that he was believed to be preparing to make an asylum application. The U.S. consulate did not respond to a request for comment. Like other anti-government organisations, Studentlocalism disbanded before, Studentlocalism disbanded before Beijing imposed the national security law.