Wu’er Kaixi, a student leader in the 1989 Tiananmen pro-democracy protests, has been released from custody after allegedly trying to force his way into the Chinese Embassy in Tokyo last week.

A massive police presence ringed China’s Tiananmen Square today, the 20th anniversary of the bloody crackdown on pro-democracy activists, as the government continued an overwhelming drive to muzzle dissent and block commemorations.

Fifteen years after the bloodshed, the exiled student leaders of China’s 1989 pro-democracy protests are settled abroad as academics and entrepreneurs. But they nurture one wish above all – to come home to a new system.