“Bomb blast stuns Central,” ran a South China Morning Post headline on April 1, 1981. The explosion “ripped through the 16th floor of the 17-storey building shortly after a hand-delivered note demanding $500,000 was reportedly received” at the Shell oil company’s headquarters, injuring 22-year-old “office messenger” Chan Kwok-wai. “A tooth, his tie, broken spectacles and a fountain pen” were found near the spot where Chan was flung by the blast. The explosion followed a 14-month spate of bombings “and few clues as to which individuals or groups are responsible”, with the most recent incident occurring just a week before the Shell company was targeted, the Post reported. “A theory rapidly gaining ground in some quarters is that gangs of well-disciplined illegal immigrants from China are behind some of the latest incidents of reported bomb extortion cases.” “Last month, pigeons were used as couriers for sending extortion notes with instructions to the company demanding that the money be tied to the birds’ feet” The South China Morning Post On August 19, a pedestrian was injured in an explosion at the Shell oil depot in North Point. “Shell appears to be targeted for acts of terrorism,” reported the Post on August 21. “Two months after the March attack, bomb threats were received by several of the company’s branches in Kowloon and the New Territories.” Chong Shing-keung, 29, a former soldier of the People’s Liberation Army, was arrested on August 25 on suspicion of causing both explosions. When a Hongkonger hijacked a Beijing-bound flight as a ‘gesture against communism’ “Last month, pigeons were used as couriers for sending extortion notes with instructions to the company demanding that the money be tied to the birds’ feet,” reported the Post . Chong was found guilty of two charges of causing an explosion likely to endanger life and property, one of blackmail and one of possession of explosive substances. He was sentenced to 15 years in prison in May 1982.