China should release at least 76 people, detained on the mainland for supporting Hong Kong's pro-democracy protests, before the start of next week's Asia-Pacific leaders summit in Beijing, rights group Amnesty International said on Friday.
Students calling for full democracy for Chinese-ruled Hong Kong have blocked roads leading into three of the city's most economically and politically important districts for weeks, drawing condemnation from Beijing and the Hong Kong government.
Leaders including US President Barack Obama, Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping will gather for the Nov 10-11 Asia Pacific Economic Cooperation (APEC) summit in the Chinese capital.
Preliminary meetings are already underway.
"APEC leaders must end their recent silence on the crackdown against mainland Chinese activists expressing support for Hong Kong pro-democracy protesters. Political convenience should not trump principled action," said Roseann Rife, East Asia Research Director at Amnesty International.
"The leaders should take this opportunity to speak out and urge President Xi to ensure all those detained solely for exercising their right to freedom of expression and peaceful assembly are immediately and unconditionally released," she said in a statement.
China's foreign ministry did not immediately respond to a request for comment on Amnesty's statement.
Beijing has ruled Hong Kong since 1997 through a "one country, two systems" formula that allows wide-ranging autonomy and freedoms not enjoyed on the mainland.
The protesters are demanding fully democratic elections for the city's next chief executive in 2017, not the vote between pre-screened candidates that Beijing has said it would allow.
Amnesty said the detentions in China have been especially concentrated in Beijing, as well as the southern cities of Guangzhou and Shenzhen that abut Hong Kong.
People have been held for putting pictures online with messages of support, planning to go to Hong Kong to take part in the protests or shaving their heads in solidarity, it said.
The government has stepped up security in Beijing ahead of the summit. Amnesty said some activists had been forced to leave the city, including prominent dissident Hu Shigen.
Xi has presided over a sweeping crackdown on the rights community since taking office two years ago and, while he has promised to improve the rule of law, the Communist Party will remain firmly in charge of the judicial system.
"The latest wave of detentions is part of a concerted attack on fundamental freedoms since President Xi took office. It makes a mockery of Xi's recent claims that the rule of law and human rights will be fully respected in China by 2020," Rife said.