China rounds up dissidents, blocks Twitter

BEIJING – Ahead of the 20th anniversary of the bloody crackdown on Tiananmen Square this week, Chinese authorities have rounded up dissidents and shipped them out of town. Now, they've even shut down Twitter.

Along with their usual methods of muzzling dissent, the authorities extended their efforts Tuesday to silence social networking sites that might foster discussion of any commemoration of the events of June 3-4, 1989.

China has never allowed an independent investigation into the military's crushing of the 1989 protests, in which possibly thousands of students, activists and ordinary citizens were killed. The subject remains taboo on the mainland, with officials routinely countering questions about Tiananmen with remarks on how much China has developed and prospered in the years since.