Wall Street Journal proprietor Rupert Murdoch says that Chinese hackers are still attacking his newspaper, suggesting the spying campaign against U.S. journalists unveiled last week is still live.

In a brief message posted to Twitter, Murdoch said late Tuesday that "Chinese still hacking us, or were over weekend."

The Journal is one of a series of news organizations that have revealed that they were hit by what have been described as China-based hackers.

The New York Times and The Washington Post have also reported that their computer systems were breached in similar incidents, while Bloomberg News said it managed to deflect a hacking attempt.

Messages seeking further comment from Dow Jones, the Journal's publisher, were not immediately returned Wednesday.