BEIJING (AP) — Yin Min held the ashes of her son and wept, she said, as she marked 25 years since he was killed in the crackdown by Chinese tanks and troops on protests at Tiananmen Square. Outside, guards kept a close eye on her home while police blanketed central Beijing to block any public commemoration of one of the darkest chapters in recent Chinese history.

“How has the world become like this? I don’t even have one bit of power. Why must we be controlled so strictly this year?” Yin said in a telephone interview. “I looked at his ashes, I looked at his old things, and I cried bitterly.”