Police were lining the streets around the headquarters of the Southern Weekly in Guangzhou on the first anniversary of a rare protest supporting journalists who went on strike after a row with censors.
A heavy police presence could be seen outside the company's offices beginning on Saturday, with uniformed and plain-clothes officers patrolling the entrance and nearby streets and alleys yesterday.
Five civil rights activists were detained by police this weekend, in addition to two detained earlier, in August and March.
Hundreds of people gathered outside the newspaper's office on January 7 last year to stage a series of peaceful demonstrations in support of the striking journalists. The editorial staff at the paper were unhappy about government censorship of a New Year's editorial calling on central authorities to implement the country's constitution.
A Southern Weekly employee, who asked not be named, said the authorities had wanted to stop any repeat of last year's protests.
"Precautionary measures are in place because of the one-year anniversary of the Southern Weekly incident," the employee said. "The police presence has not affected our work. We just needed to take a bigger detour to fetch things."
Courier company employees, who usually deliver and collect packages from the building's main entrance, were told to move to a narrow alley nearby to stop people gathering outside the offices.
Guangzhou civil rights lawyer Liu Shihui , who is representing protesters detained last year, was held at a police station in Guangzhou on Sunday.
At least four other activists were detained by dozens of police officers while meeting at a flat on Saturday evening, according to Guangzhou-based civil rights lawyer Tang Jingling . Friends of the activists said they were all still in police detention.
Two of the demonstrators who took part in the protests last year are expected to go on trial soon on charges of "gathering a crowd to disrupt public order''.
Civil rights activist Liu Yuandong was first detained in March and later charged for his role in the protests.
The other activist, Yang Maodong , who is better known by his pen name Guo Feixiong , was detained in August. He told family members the police considered him the mastermind behind last year's demonstrations.
In its New Year's editorial last week, the newspaper said it insisted on its right to "express the truth" but avoided any direct mention of last year's incident. Some readers expressed disappointment online with the philosophical message.