The Guardian newspaper said on Monday that its Twitter accounts have been hacked, and it cited a claim of responsibility from the group calling itself the Syrian Electronic Army.
The British paper reported on its website that several of its feeds on the social media site were broken into over the weekend. It said that it has since discovered that the attack apparently originated from Internet protocol addresses within Syria.
"We are aware that a number of Guardian Twitter accounts have been compromised and we are working actively to resolve this," said a statement from Guardian News and Media, the company that publishes the paper.
The Syrian Electronic Army is a shadowy group that supports the regime of Syrian President Bashar Assad, which is battling an armed uprising.
The group has claimed responsibility for a string of Web attacks on other media targets, including The Associated Press. The Guardian said the group accused it of spreading "lies and slander about Syria."
Hackers attacked the AP's Twitter accounts last week, sending out a false tweet about an attack on the White House and triggering a brief plunge on the US stock market.
The Guardian said it first recognized it was being targeted when suspect emails were sent to staff members to trick them into giving away security details. Some of the paper's Twitter accounts, including those focusing on books and film, were suspended Monday.