From AFP, via the Standard (link):
Hundreds of people have been detained as authorities crack down on dissent before the National People’s Congress, petitioners and a rights lawyer said.
Police raided hostels near the south Beijing train station Tuesday night and rounded up more than 400 people who had come to air their grievances through China’s unique petition system, petitioners said Wednesday.
“Seven or eight goods vehicles took them away … I heard they will come back again to arrest more people tonight,” said Qian Lili, a woman trying to lobby for a fair trial over the murder of her son several years ago.
Another petitioner surnamed Chen and lawyer Gao Zhisheng, who has advised many petitioners, confirmed the news by phone before they were cut off.