(FILES) This file photo taken on June 4,

(FILES) This file photo taken on June 4, 1989 shows an armoured personnel carrier in flames as students set it on fire near Tiananmen Square in Beijing. Hundreds, possibly thousands, of protesters were killed by China's military on June 3 and 4, 1989, as communist leaders ordered an end to six weeks of unprecedented democracy protests in the heart of the Chinese capital. Dissidents and human rights advocates around the world will mark on June 4, 2009 the twentieth anniversary of China's bloody crackdown on the pro-democracy protests. AFP PHOTO / FILES / TOMMY CHENGAn armoured personnel carrier is in flames as students put in on fire 04 June 1989 near Tiananmen Square in Beijing. On the night of 03 and 04 June 1989, Tiananmen Square sheltered the last pro-democracy supporters. A series of pro-democracy protests was sparked by the April 15 death of former communist party leader Hu Yaobang. In a show of force, China leaders vented their fury and frustration on student dissidents and their pro-democracy supporters. Several hundred people have been killed and thousands wounded when soldiers moved on Tiananmen Square during a violent military crackdown ending six weeks of student demonstrations, known as the Beijing Spring movement. According to Amnesty International, five years after the crushing of the Chinese pro-democracy movement, "thousands" of prisoners remained in jail. AFP PHOTO TOMMY CHENG (Photo credit should read TOMMY CHENG/AFP via Getty Images)