"Starting at 16:45 GMT, the Twitter account of AFP's photo service @AFPphoto was hacked. The documents posted after that on the account did not originate from the agency," the statement said.
The account has since been suspended and AFP is working to restore it.
Most of the images posted by the hackers after the site was hacked were related to the conflict in Syria.
At the same time, AFP has been the victim since Monday morning of a so-called "phishing" attack designed to steal the identifications and passwords of agency employees by luring them into logging onto a fake AFP website.
The attack was still under way but has so far been successfully repelled, AFP's security experts said.
It was not clear as of Tuesday night whether the two hacking episodes were related.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ