Journalists from several media outlets covering recent floods in China were harassed online and by local residents, with staff from the BBC and Los Angeles Times receiving death threats, according to the Foreign Correspondents' Club of China (FCCC).
In a statement on Tuesday, the FCCC criticised what it said was growing hostility to foreign media, some of which it said was fanned by official bodies.
"There must be immediate action by the Chinese government to stop these attacks which continue to endanger foreign journalists," the BBC said in a statement on Twitter.
China's foreign ministry did not immediately respond to requests for comment on the FCCC and BBC statements.
A spokesperson for the Los Angeles Times did not immediately respond to a request for comment sent after office hours.
In one incident, the local branch of the ruling Communist Party's Youth League had asked its social media followers to report the whereabouts of a BBC reporter covering the floods, according to the FCCC statement.
"Rhetoric from organizations affiliated with China's ruling Communist Party directly endangers the physical safety of foreign journalists in China and hinders free reporting," it said.
Chinese nationals working for foreign media have also been threatened and accused of treason online, the FCCC said.
China's foreign ministry has publicly criticized what it calls "fake news" from Western news outlets including the BBC. One BBC journalist, John Sudworth, left the country this year citing threats of legal action, obstruction and intimidation.
China's foreign ministry said at the time it had never threatened Sudworth.
Some Reuters journalists are members of the FCCC.