The BBC has condemned jamming of its World Service shortwave radio system in China. The corporation says it's received reports that attacks on shortwave frequencies are "being timed to cause maximum disruption to BBC World Service English broadcasts in China." While it couldn't pinpoint the source, "the extensive and coordinated efforts are indicative of a well-resourced country such as China."

The BBC has previously seen its satellite TV signals jammed in places with tightly controlled media. In October, both it and other broadcasters' signals were being cut off within Syria, and Iran has done similar jamming, a practice that violates international broadcasting treaties. Shortwave radio jamming, the BBC says, is less frequent, but China has a long history of blocking US-funded programs like Radio Free Asia or Voice of America.

"The extensive and coordinated efforts are indicative of a well-resourced country such as China."

Over the past month, the New York Times, Wall Street Journal, and Washington Post have all reported hacks allegedly by the Chinese military, and a BBC reporter was briefly detained for taping video outside a building that's been pegged as the source. While China has denied any involvement, this jamming is another sign of the tense relationship it maintains with news media.