Chinese police beat a BBC journalist in Shanghai and briefly arrested him while he was covering anti-government lockdown protests gripping the nation.
Ed Lawrence was detained at the main protest in the city on Sunday, and held for several hours before being freed.
"It is very worrying that one of our journalists was attacked in this way whilst carrying out his duties," the BBC said.
China's government said Mr Lawrence hadn't presented his press credentials.
He had been filming the crowds at the nation's largest protest in Shanghai at Wulumuqi Middle Road on Sunday.
Footage shared widely on social media showed several police officers grabbing Mr Lawrence and pinning him to the ground. The BBC said he was beaten and kicked by police officers, and then taken away in handcuffs.
The broadcaster said the treatment of its journalist was "extremely concerning".
In a statement, it said it had not received an official explanation or apology from China, "beyond a claim by the officials who later released him that they had arrested him for his own good in case he caught Covid from the crowd".
"We do not consider this a credible explanation."
At a regular press conference on Monday, China's foreign ministry spokesman did not address the police violence and arrest of an accredited foreign journalist.
"Based on what we learned from relevant Shanghai authorities, he did not identify himself as a journalist and didn't voluntarily present his press credentials," spokesman Zhao Lijian said.
Mr Lawrence re-tweeted the BBC's statement on Monday and added that he was aware of at least one local who had also been arrested "trying to stop the police from beating me".
The Foreign Correspondents Club of China said it was "extremely disturbed" by the treatment of reporters covering the protest.
At least one other foreign journalist - a Swiss national - was also briefly arrested elsewhere in the city on Sunday.
"Journalists from multiple outlets were physically harassed by police while covering the unrest, and at least two journalists were detained," the FCC said.
"In one particularly alarming incident, a British journalist was seen being wrestled to the ground by multiple officers before being led away."
It noted that under Chinese law, foreign journalists were "entitled to unfettered access to report in China."
Protests against the Chinese government and its Covid lockdown policies have erupted across a number of cities after a deadly fire in the western region of Xinjiang killed 10 people last week.
Many believe residents couldn't escape the blaze in a locked-down apartment tower in the city of Urumqi because of Covid restrictions. Local authorities have disputed this.
Public anger over the tragedy - just the latest in a series of disasters blamed on Covid restrictions - escalated into street protests across several Chinese cities.
The Chinese government has not acknowledged the protests or responded in any formal way. However news of the protests has spread rapidly through Chinese social media despite heavy censorship.
The UK government condemned the Chinese police detention of Ed Lawrence, with a minister saying it was "deeply disturbing".
Foreign Secretary James Cleverly wrote on Twitter that "journalists must be able to do their job without intimidation".