A group calling itself the Syrian Electronic Army is claiming that it has infiltrated 11 Guardian Twitter accounts in the past few days.
The hacked accounts are said to include @guardianbooks, @guardiantravel, @guardianfilm, @guardianstage and @guardianphotos.
A blog post written by the SEA claims the group obtained access to accounts including those belonging to assistant editor Michael White and environment editor John Vidal.
According to the website ZDNet, the SEA posted tweets on the hacked accounts saying: "Follow the Syrian Electronic Army…Follow the truth!"
Journalists Claire Phipps and James Ball, on Twitter, reported that the Guardian office had received a number of “robot phone calls” apparently related to the hacking.
A Guardian News & Media spokesperson said "We are aware that a number of Guardian Twitter accounts have been compromised and we are working actively to resolve this.”
According to a Guardian report staff first realised they were being targeted over the weekend when spoof emails were recieved "encouraging them to click on links that could compromise some of the company's email and social media accounts".
It was described as a "classic, if crude, "phishing" attack" and the paper has discovered that the attack originated from IP addresses in Syria.
The Guardian report claimed the attacks were "an apparent effort to cause disruption and spread support for President Bashar al-Assad's regime".