The Guardian has said its Twitter accounts have been targeted by pro-Syrian government hackers.
According to the newspaper, a group calling itself the Syrian Electronic Army (SEA) claimed responsibility for the attack.
The GuardianBooks, GuardianTravel and guardianfilm accounts were among those affected by supporters of President Bashar Assad's regime.
Last month several official BBC Twitter accounts were hacked by the same group.
A Guardian News and Media spokesman said: "We are aware that a number of Guardian Twitter accounts have been compromised and we are working actively to resolve this."
Emails were sent to the newspaper's staff over the weekend encouraging them to click on links that could provide access to social media accounts.