Authorities in Beijing have banned sales of natural gas canisters and knives, as the city began to fill up with military personnel on the eve of the ruling Chinese Communist Party (CCP)'s centenary celebration on July 1.
Internet connections in the capital have also been intermittent in recent days, local residents told RFA.
Businesses in Beijing are required to mail knives to customers after the event, while sales of natural gas have been temporarily suspended until July 4, according to a directive sent to community groups.
Dissidents across the city remain under close surveillance, with many taken out of town on forced "vacations" by state security police, political commentator Zha Jianguo said.
"There have been police officers on guard [outside my home] since yesterday," Zha said. "Two security guards and three others sent by police outside the door."
"This is because of the centenary, and they have been there since June 15," he said. "They were only there for six days around the anniversary of June 4 [1989]."
"Our freedom of movement is gone, as well as our basic human rights," he said.
Ji Feng, a former participant in the 1989 pro-democracy movement, has been taken to the Baiyangdian Resort in Hebei province, neighboring Beijing, in custody of state security police.
Meanwhile, a petitioner from northeastern China who gave only a surname, Wang, said there are police on guard outside her apartment in Beijing's Daxing district, where large numbers of people pursuing complaints against the government are living temporarily.
"Two police officers in uniform arrived outside our home yesterday," Wang said. "They are also going door-to-door checking IDs."
"If they catch you, they will take you back [to your hometown]," she said.
'Knocking on doors'
A petitioner surnamed Zhang said officials had also been around the "petitioner village" confiscating natural gas bottles used for cooking.
"They've been knocking on doors and checking to see if the bottled gas was taken away yet," Zhang said. "[They are also taking] car batteries away."
"The mobile signal has been terrible in Beijing during the past few days ... [and] basically the internet connection comes and goes," Zhang said.
Government censors have also moved in recent days to shut down large numbers of groups on the social media platform WeChat, a user told RFA.
"They are shutting down groups in Beijing," the user said. "It seems that they shut down one of our groups every day."
A Beijing resident surnamed Zhao said all communications signals will be jammed around Tiananmen Square around the time of the centenary parade, from around 8.00 a.m. to noon, between Dongdan and Xidan, as well as some parts of the Second Ring Road.
Speaking at a courtyard home-turned-memorial hall where Mao Zedong and 12 others founded the party in 1921, CCP general secretary Xi Jinping on Monday called on party members to "sacrifice everything" for the party.
No past mistakes
Xi has presided over the public erasure of dissenting opinions, as well as over a growing insistence that the party's past mistakes not be alluded to in public debate.
The party is now campaigning against "historical nihilism," which is defined as any attempt to use the past to question the party's current version of events, or its role in modern Chinese history.
According to Xi, his "socialism with Chinese characteristics for the new era" will produce more revolutionary heroes willing to sacrifice their lives for the people.
The number of CCP members recently topped 95 million, according to the party's organization department.
But Yang Haiying, a professor at Shizuoka University in Japan, said many members join to further their life chances, rather than to spend a life working to improve the lot of ordinary Chinese.
"There is a lot of competition to join the party right now," Yang told RFA. "When college students join the party during their time at university, they are all doing it so they can become civil servants."
"It's sheer pragmatism," he said.
Zha Jianguo agreed.
"It's a good idea to join the party right now; everyone knows that," he said. "That's if you want a government career, or to win promotion."
"It's a basic prerequisite."
Reported by Qiao Long for RFA's Mandarin Service. Translated and edited by Luisetta Mudie.