Authorities in Beijing have stepped up security around the Egyptian embassy after Chinese citizens began leaving wreaths of flowers to congratulate the Egyptian people on the toppling of president Hosni Mubarak.
"There are a lot more [armed police] around than usual," said petitioner Zhou Li, who was at the scene. "We saw a lot of armed police arriving and taking up their posts there."
"Where previously there was one on duty, now you have three ... at intervals of every few meters," she said. "There were too many to count."
Zhou said she had been unable to take part in the wreath-laying campaign, which has been largely coordinated via microblogging services like Twitter.
"If you ask one of the armed police where it is ... they just shake their head and refuse to tell you, or they give you false directions," she said.
She said three Chinese rights activists who did get to the embassy were detained by local police after they tried to show public support for the Egyptian popular uprising.
"We got to the embassy gate and they detained us," said petitioner Wang Xueqin, who was with fellow activists Zhang Xiuhua and Su Wenjuan at the time.
"Then they demanded our identity cards ... then they stopped us from going in [to the embassy compound]."
"I told them I wanted to congratulate the Egyptians on the victory of democracy in my own manner, and that there was nothing wrong with this," Wang said. "It's not against the law."
"I told them this advanced the cause of democracy, and then they refused to let us go and called over the national security police who took our photographs."
He said the three activists were held for about an hour before being allowed to leave the embassy district and go home.
"At about 9 or 10 p.m. the police called us to ask who had organized us to do this," Wang said. "I told them no one had, that these were our individual actions."
Sichuan-based rights activist Ran Yunfei said that similar actions in the Iranian capital Tehran had been met by a police guard at nearby subway stops, not with the detention of supporters of the Egyptian protests.
"This just goes to show that the Chinese regime secretly keeps an even tighter control on society than the one in Iran," Ran said.
Meanwhile, activist Liao Shuangyuan was detained by national security police in the eastern province of Zhejiang, friends and family said.
Liao was taken from the home of environmental activist Jin Biao as he was about to eat lunch, Jin said.
"There were already secret agents following him," Jin said. "They said they wanted to ask him some questions ... They were very forceful."
"After that, when Bi Mingkai left my house, there were three vehicles tailing him," Jin added.
Beijing-based rights activist Liu Shasha said more people might have supported the campaign if it were not for tight controls on Chinese Internet users.
"Only a few people who like to scale the Great Firewall will know what was going on in Egypt," Liu said. "The authorities have always kept a tight grip on the Internet."
"They also divert public attention so that most people don't care about it, as well," she added.
Chinese authorities have imposed strict online censorship and a careful campaign aimed at limiting public reaction during the recent protests in Tunisia and Egypt.
According to a recent report from the Shanghai Academy of Social Sciences, Beijing's domestic security spending is fast catching up to the level of spending on the country's massive military budget.
Government figures have recorded tens of thousands of "mass incidents" across the country every year, often sparked by land disputes, forced evictions or allegations of corruption against local officials.
China's ruling Communist Party recently set up an office for maintaining stability, sending out guidelines and directives to every bureaucratic and law enforcement agency down to village and neighborhood committee level, experts say.
Officials and Internet service providers have removed hundreds of millions of items of unwanted news from the Chinese Internet, government figures show.
Reported by Xin Yu for RFA's Mandarin service and by Wen Yuqing for the Cantonese service. Translated and written in English by Luisetta Mudie.