Radio broadcasts in English from the BBC World Service are being jammed in China, the British broadcaster said on Monday, suggesting the Chinese authorities were behind the disruption.
"The BBC strongly condemns this action which is designed to disrupt audiences' free access to news and information," the BBC said in a statement.
China, which enforces strict restrictions on its domestic media, has been accused by several prominent foreign media of seeking to stop their news reports reaching Chinese audiences.
"The BBC has received reports that World Service English shortwave frequencies are being jammed in China," said the London-based public service broadcaster.
"Though it is not possible at this stage to attribute the source of the jamming definitively, the extensive and coordinated efforts are indicative of a well-resourced country such as China."
A duty officer at China's foreign ministry had no immediate comment.
It was not the first time the BBC had complained of disruption to its services in China, where its website has been consistently blocked.
Last year, it accused the Chinese authorities of jamming its BBC World News TV channel when it broadcast stories regarded as sensitive, such as reports on dissident Chen Guangcheng, who escaped from house arrest and sought refuge in the U.S. embassy.
Other foreign broadcasters including U.S. state-funded radio stations Voice of America and Radio Free Asia have also complained of Beijing blocking access to their programmes.
The New York Times reported on January 30 that Chinese hackers had been attacking its computer systems while it was working on an investigative report in October last year on the fortune accumulated by relatives of outgoing Premier Wen Jiabao.
The BBC said in its statement on Monday that it had experienced jamming of satellite broadcasts over the past two years, and that while shortwave jamming was generally less frequent, it did also affect Persian-language transmissions in Iran.
"The jamming of shortwave transmissions is being timed to cause maximum disruption to BBC World Service English broadcasts in China," said Peter Horrocks, director of BBC Global News.
"The deliberate and coordinated efforts by authorities in countries such as China and Iran illustrate the
significance and importance of the role the BBC undertakes to provide impartial and accurate information to audiences around the world."
China is listed at number 173 out of 179 countries on the World Press Freedom Index compiled by campaign group Reporters Without Borders.
© Thomson Reuters 2013