Yin Min held the ashes of her son and wept as she marked 25 years since he was killed in the crackdown by Chinese tanks and troops on protests at Tiananmen Square.

Beijing is blanketed in heavy security today, the 25th anniversary of the bloody military suppression of pro-democracy protests centred on Tiananmen Square.

The father of a man killed in the 1989 Tiananmen Square crackdown has hanged himself after two decades of failed attempts to seek government redress.