The new X logo at the company's headquarters in San Francisco, California on July 29, 2023.
London CNN  — 

X says it has removed “hundreds of Hamas-affiliated accounts” and taken down thousands of posts since the attack on Israel by the Palestinian militant group, even as the European Commission formally opened an investigation into X after a previous warning about disinformation and illegal content on its platform linked to the Israel-Hamas war.

The platform, formerly known as Twitter, was given 24 hours by the European Union earlier this week to address illegal content and disinformation regarding the conflict or face penalties under the bloc’s recently enacted Digital Services Act.

CEO Linda Yaccarino responded to EU official Thierry Breton in a letter dated Wednesday that she posted to X. She said the company had “redistributed resources and refocused internal teams who are working around the clock to address this rapidly evolving situation.”

“There is no place on X for terrorist organizations or violent extremist groups and we continue to remove such accounts in real time,” Yaccarino wrote.

“X is… addressing identified fake and manipulated content during this constantly evolving and shifting crisis,” she added. The platform had “assembled a leadership group to assess the situation” shortly after news broke about the attack, Yaccarino said.

European Union officials are now assessing X’s compliance with the DSA and have asked the company to start responding to investigators by as early as Oct. 18.

The probe covers X’s “policies and practices regarding notices on illegal content, complaint handling, risk assessment and measures to mitigate the risks identified,” the Commission said in a release.

“X is required to comply with the full set of provisions introduced by the DSA since late August 2023,” the release added, “including the assessment and mitigation of risks related to the dissemination of illegal content, disinformation, gender-based violence, and any negative effects on the exercise of fundamental rights, rights of the child, public security and mental well-being.”

X didn’t immediately respond to a request for comment. Beyond X, European officials have sent similar warnings to Meta and TikTok in recent days.

The announcement did not name the Israel-Hamas war. But this week, EU officials sent a letter to X owner Elon Musk warning that if an investigation finds that the company had failed to meet its legal obligations in connection with content about the war, it could face steep penalties, including billions in fines.

A slew of mischaracterized videos and other posts went viral on X over the weekend, alarming experts who track the spread of misinformation and offering the latest example of social media platforms’ struggle to deal with a flood of falsehoods during a major geopolitical event.

Since the attack on Israel, Yaccarino said X had acted to “remove or label tens of thousands of pieces of content” that break its rules on violent speech, manipulated media and graphic media. It had also responded to more than 80 “take down requests” from EU authorities to remove content.

“Community Notes” — which allow X users to fact check false posts — are visible on “thousands of posts, generating millions of impressions,” she wrote.

According to Yaccarino, notes related to the conflict take about five hours on average to show up after a post is created, a revelation that could fuel concerns that fake or manipulated content is being seen by thousands — or in some cases millions — of people before being moderated.

The DSA is one of the most ambitious efforts by policymakers anywhere to regulate tech giants and companies face billions in fines for violating the act.