Authorities in the central Chinese province of Hunan on Tuesday detained a prominent rights activist who led an ongoing vigil calling for the release of 10 people who tried to commemorate this year's anniversary of the Tiananmen Square crackdown.
Meng Xiaodong was taken away by plainclothes police officers in the provincial capital Zhengzhou, according to fellow activist Liu Linna, also known as Liu Shasha.
"He was detained and taken away by police from [nearby] Xingyang city at around 6:00 a.m.," Liu told RFA. "I got a phone call from him saying that the Xingyang municipal police department was refusing to explain anything."
"They said they were just here to detain him, and waiting for the Zhengzhou municipal police to come and fetch him," she said.
Meng was detained after taking part in a rolling vigil outside two Zhengzhou detention centers where seven activists are being held for holding a memorial to mark the 25th anniversary of the 1989 crackdown on a student democracy movement and two late former premiers, Hu Yaobang and Zhao Ziyang.
Repeated calls to Meng's cell phone resulted in a "switched off" message on Tuesday.
Calls to the Xingyang municipal police department rang unanswered during office hours.
Zhengzhou petitioners Jia Lingmin and Liu Diwei, activists Chen Wei, her husband Yu Shiwen, Hou Shuai, Fang Yan and Dong Guangping were formally arrested on public order charges earlier this month after being detained at the end of May.
Journalists Shi Ping, who goes by the pen-name Shi Yu, Yin Yusheng and Shao Shengdong were also detained around the same time, but Shi and Shao were later released on bail, according to the Chinese rights website Weiquanwang. Yin Yusheng is under criminal detention rather than formal arrest.
Two lawyers hired by those arrested, Chang Boyang and Ji Laisong, were also formally arrested.
The majority of the group have been charged with "picking quarrels and stirring up trouble," while Chang has been charged with "conducting an illegal business," Weiquanwang said.
"They are all ordinary people who want a normal society; who want to work hard to become citizens, not subjects," the group said in a statement on its website on Tuesday.
The arrests sparked a campaign for their release which spread rapidly online, and dozens of activists have converged on Zhengzhou in recent days to take part in a protest for their release.
Activists are keeping up a presence outside the jails around the clock, working in shifts outside the Zhengzhou Municipal No. 2 and No. 3 Detention Centers, where the seven are being held, Liu said.
"There are ... about nine or 10 people outside the No. 3 and another group of maybe four or five outside the No. 2," she said.
Speaking from outside the No. 3 detention center, campaigner Di Yanmin said the group was continuing to shout slogans of protest at the arrest of the "Zhengzhou 10."
"We will continue to protest," Di said. "They haven't [tried to stop us] yet, and we will step up our efforts every day."
"There are eight people inside the No. 3 detention center: Chang Boyang, Ji Laisong, Dong Guangping, Yu Shiwen, Chen Wei, Hou Shuai, Jia Lingmin and Liu Diwei," he said.
Jiangxi-based petitioner Gong Xinhua said he was also taking part.
"I don't know the people being held inside, personally, but I care what happens to them," Gong said. "I think the authorities should give us an explanation."
He said many of those taking part have been under close police surveillance for days.
"They were keeping watch over us where we were staying, so we moved elsewhere," Gong said. "They photograph and shoot video of us, but that's as far as it's gotten so far."
"They haven't sent us away yet."
He said the situation remains unpredictable, however. "They don't act according to the law," Gong said.
Authorities detained dozens of activists, lawyers, academics and journalists before the 25th anniversary of the Tiananmen Square bloodshed, and tightened controls on dissent, free speech and the Internet.
Many of those who were placed under house arrest or taken on enforced "vacations" were later released, while others face trial on public order charges similar to those the Zhengzhou 10 are accused of.
The ruling Chinese Communist Party bans public memorials marking the event, although police have escorted the relatives of those who died from house arrest to cemeteries to pay their respects to loved ones in private.
The party has continued to ignore growing calls in China and overseas for a reappraisal of the 1989 student protests, which it once styled a "counterrevolutionary rebellion."
The number of people killed when People's Liberation Army tanks and troops entered Beijing on the night of June 3-4, 1989 remains a mystery.
Beijing authorities once put the death toll at "nearly 300," but the central government, which labelled the six weeks of pro-democracy protests a "counterrevolutionary uprising," has not issued an official toll or list of names.
Reported by Qiao Long for RFA's Mandarin Service, and by Wen Yuqing for the Cantonese Service. Translated and written in English by Luisetta Mudie.