HONG KONG—Hong Kong police arrested six activists on Wednesday for suspected sedition and contravention of a national security law in connection with what the police called “causing nuisance” at court hearings in December and January. Police, who typically do not identify arrested people, said the six were aged 32 to 67, had been arrested for “having purposely caused nuisance” during various court hearings they attended. They had been being detained for further investigation, police said. Media said those arrested included Leo Tang, a former vice-chairman of the now disbanded Confederation of Trade Unions (HKCTU), and citizen journalist Siew Yun-long. The six were accused of “affecting jurisdictional dignity and court operations” at the High Court, the West Kowloon Magistrates’ Courts and the Eastern Magistrates’ Courts, between December 2021 and January 2022. Police did not say what the suspects had allegedly done. Police raided their homes and seized “records of conspiracy to …