Two full years after the People's Liberation Army shot its way into Tiananmen Square, the trauma of June 3-4, 1989, continued to cast a dark shadow over the Chinese political scene. Following an initial wave of peremptory arrests, beatings, and well-publicized executions of alleged "hooligans" and "thugs," the Chinese government early in 1990 began to limit the scope and intensity of its judicial reprisals. In the winter of 1989, a series of violent clashes between Buddhist demonstrators and Chinese security forces, in which hundreds were killed, led to the imposition of martial law and the banning of foreign media. Trained in Moscow as a hydroelectric engineer in the 1950s, Li became China's minister of electric power industry in the 1970s; in 1985 he was tapped to become vice prime minister of the State Council. By 1988, Li and Zhao Ziyang had become clear rivals for power, and it was Li who benefited most directly from Zhao's dismissal.