Social messaging site Twitter has been hacked by a group calling themselves the Iranian Cyber Army.

CNN is reporting that Twitter’s website was down for about one hour, during which time tweeters were redirected to another site featuring a picture of a green flag and the words “This site has been hacked by Iranian Cyber Army”.

Following the attack, Twitter’s co-founder Biz Stone, said: “Twitter’s DNS records were temporarily compromised but have now been fixed. As some noticed, Twitter.com was redirected for a while but API and platform applications were working. We will update with more information and details once we’ve investigated more fully.”

Earlier this year Twitter was widely used by people in Iran to communicate with the rest of the world during protests following the county’s disputed presidential election.