Hong Kong police raided a museum commemorating the 1989 Tiananmen Square crackdown, removing exhibits and arresting four members of the group that ran the museum. The arrests were made under the national security law, which has a maximum sentence of life imprisonment. The museum was closed down by officials in June, and the raid was carried out by the newly created national security unit. The group that ran the museum denies accusations of being a foreign agent and has refused to cooperate with requests for information.