envoys reported the deployment in late August of a sizeable number of People's Liberation Army (PLA) troops to Hong Kong, well beyond the usual rotation and possibly doubling the number of PLA troops compared to before the start of the protests. Drills by the People's Armed Police were observed across the border in Shenzhen in August. On 6 October 2019, the PLA issued its first warning to the protesters, who were shining laser lights on the exterior of the PLA garrison in Kowloon Tong. On 16 November, soldiers appeared publicly in the streets for the first time during the protests, in plain clothes and unarmed, to clear roadblocks and other debris left during protests alongside local residents, firefighters, and police officers before marching back to the Kowloon Tong barracks. The government insisted the soldiers were volunteers, and that it had made no request for assistance. The act was criticised by pro-democrats who deemed it a violation of the Basic Law. The Chinese government required goods mailed from mainland China to Hong Kong to be investigated while goods which were believed to relate to the protests were blocked. Chinese authorities also detained several individuals in mainland China after they voiced their support for the protesters. China further tightened its control in Hong Kong in 2020: on 4 January, the State Council dismissed Wang Zhimin from the role of director of the Hong Kong Liaison Office and appointed Luo Huining as his successor. The decision was widely linked to the poor performance of pro-government candidates at the District Council elections in November, and Wang's perceived poor judgment of how the protests evolved. Hong Kong and Macau Affairs Office director Zhang Xiaoming was demoted and replaced by Xia Baolong in February 2020. The new directors triggered the Basic Law Article 22 controversy in April when they claimed that the two offices were not covered by Article 22. In May, China announced that the NPCSC, China's rubber-stamp legislative body, would directly draft a national security law for Hong Kong and skip the local legislation procedures. Political analysts believed that Beijing's action would mark the end of the "one country, two systems" principle and Hong Kong's autonomy as promised in the Sino-British Joint Declaration. On 28 May 2020, the NPC approved the controversial national security laws for Hong Kong. The legislation allows the government's national security agencies to operate in Hong Kong. On 30 June