BEIJING, China (AFP) — A young protester has been held in police detention in southern China for nine days after taking part in rallies against Covid restrictions, her mother told AFP, expressing fear and anguish over her daughter's safety.

Yang Zijing, 25, was detained on the evening of 4 December in the southern metropolis of Guangzhou after attending a protest the week before, her mother said.

"They detained so many people who were gradually released, why is she still in there?" she said.

The woman, surnamed Gao, said her daughter's roommate told her that a group of police asked to check the water meter and did not show identification when entering.

"They searched the apartment and took her away, along with her phone and laptop."

AFP has learned of multiple cases of mostly young protesters detained for up to 24 hours in Beijing and Shanghai, with police deploying sophisticated technology to track them down and threaten them in phone calls and in-person interrogations.

Gao rushed to Guangzhou on 8 December upon learning of her daughter's detention, but both she and a lawyer have been refused access to either her daughter or the police officer handling her case.

"They refused to give us any information," she said.

Under Chinese law, when an individual is taken into custody and interrogated, police have 24 hours to decide whether to release them or formally detain them.

If a suspect is detained, they must then be transferred to a pretrial detention center within 24 hours.

But Gao said police had still not transferred Yang to a detention center — allegedly due to the "epidemic situation."

A police officer at the Guangzhou station told AFP he could not comment on Yang's case over the phone.

A lawyer offering pro bono advice to protesters said on condition of anonymity that the majority of detentions she was aware of had not exceeded 24 hours.

But at least six demonstrators in Shanghai and Guangzhou had been held for a week or longer with some likely to receive criminal charges, she said.