met with heavy resistance by four jewel robbers armed with AK-47 assault rifles and hand grenades. Seven officers, including members of the Unit, were severely injured from a grenade blast. As a result of the incident, the Unit's Close Quarters Battle techniques were further refined to fit Hong Kong's unique urban environment and new equipment was added to the unit's arsenal. All suspects were apprehended. 2003: Kwai Ping-hung, the most wanted person in Hong Kong, was arrested in his flat in a raid by the Unit with no shots fired. This was the most high-profile arrest made in Hong Kong's history. 2005: During the World Trade Organization Ministerial Conference of 2005 in Hong Kong, the Unit was deployed to protect WTO delegates. 2014: In a heavily televised standoff, the Unit was deployed to a flat in a residential skyscraper in Kowloon Bay after a disgruntled man armed with a heavy calibre pistol shot and killed another man in the building and barricaded himself in the flat. Multiple shots were exchanged, along with the use of flashbang grenades, which were clearly seen and heard on live television. Several SDU officers breached the flat through the front door while others rappelled from the roof of the skyscraper and entered the flat through the windows. By the time the officers reached the man, he had shot himself. The man later died from suicide. 2019: During the Christchurch mosque shootings, two members of the Unit training in Christchurch helped respond to the shooting alongside local police by providing medical treatment to victims of the attacks. 2019-2020: During the anti-extradition protests, SDU operators as part of the Special Tactical Contingent (STC) took part in dispersing and arresting protestors. STC officers were accused of using excessive force during arrests with an Amnesty International field investigation finding that the STC was responsible for "the worst violence" by the police force. Apple Daily and New Tang Dynasty Television reported that SDU operators disguised as protesters provoked fights with protestors in order for them to be arrested. Newtalk reported that SDU operators disguised as protestors committed illegal acts such as setting fire on the street as part of a false flag operation. Police arrested a Hong Kong Museum of History employee for obstruction who uploaded photos to social media of a SDU observation post in the museum that was observing the Hong Kong Polytechnic University. See also Police Tactical