BEIJING: The 20th anniversary this week of reformist leader Hu Yaobang's death will kick off an ultra-sensitive period for China's communist rulers as they are forced to revisit the deadly Tiananmen crackdown.

Wednesday will mark the beginning of a period of heightened tension and increased security in China that will last until June 4, the date in 1989 when soldiers were sent into Tiananmen Square to crush six weeks of unprecedented democracy protests. "People have been told individually not to commemorate this," said Jean-Philippe Beja, a Hong Kong-based academic with the French Centre for Research on Contemporary China. Indeed, human rights groups and activists have said the government is making huge efforts to ensure the next two months pass smoothly, with dissidents being harassed or kept under close watch. Hu was ousted as the head of the Communist Party in 1987 for his weak response to student protests in December of the previous year.

When he died on April 15, 1989, students used his death to call for democratic reforms. The protests snowballed as a fractured leadership could not agree on how to handle the demonstrations.

"(Hu) was a symbol of the political reforms that had been stopped following his removal," said Jean-Pierre Cabestan, a China scholar at Hong Kong University.