Hackers working for Syrian dictator Bashar al-Assad have attacked the Twitter account of the Agence France Press news agency's photo department for posting pro-regime propaganda.
@AFPphoto started sending out to its more than 3,000 followers tweets blaming US president Barak Obama and anti-Assad rebels for atrocities against the Syrian population after it was hacked.
The Syrian Electronic Army claimed responsibility.
"It appears our @AFPphoto Twitter account has been hacked. Recent photos posted are not ours. Unable to delete but working on it," tweeted AFP from its main account.
"At the same time, AFP has been the victim since Monday morning of a so-called "phishing" attack designed to steal the identities and passwords of agency employees by luring them into logging on to a fake AFP website," it added later.
"The attack was still under way but has so far been successfully repelled," AFP's security experts said. It was not clear whether the two hacking episodes were related.
The hacking started with a tweet against Obama and went on with another linking to an undated picture of a Syrian square packed with people rallying "in support of their embattled president, in spite of foreign pressure".
In a third tweet, Cuban dictator Fidel Castro was compared to the president of the Syrian National Council (SNC), Abdulbaset Sieda.
A split picture of the two revolutionary leaders was posted under the header "The difference between a real revolution and a foreign-backed insurrection". It mocked Sieda for his appeals for support to the international community.
A number of graphic images depicting violence allegedly committed by Syrian rebels were also posted.
The account was suspended after an hour.
In a similar incident in August, Reuters' blogging platform was hacked by what appeared to be ro-regime hackers in Syria.
A false interview with a Syrian rebel leader claiming the FSA had pulled back from the city of Aleppo was posted on the Reuters News web site.
Twitter had its own issues with internet security recently when hackers allegedly linked to the Anonymous group gained access to user names, passwords, email addresses and other information belonging to as many as 250,000 user accounts.