Facebook revealed Friday that it had suspended "tens of thousands" of apps that may have mishandled users' personal data, part of an investigation sparked by the social media giant's entanglement with Cambridge Analytica.

The suspended apps vastly outnumber the hundreds that Facebook previously said it had taken action against. But the tech company gave little detail about what the apps had done wrong, saying only that they were associated with about 400 developers and had been targeted for a "variety of reasons."

Facebook said in a blog post Friday that it had investigated millions of apps and targeted those that had access to "large amounts of information" or had the "potential to abuse" its policies. The company said some of the apps were banned for inappropriately sharing users' data, the same violation of company policy that led to the Cambridge Analytica scandal. It added that its 18-month-old investigation isn't yet complete.

"Our goal is to bring problems to light so we can address them quickly, stay ahead of bad actors and make sure that people can continue to enjoy engaging social experiences on Facebook while knowing their data will remain safe," said Ime Archibong, the company's vice president of product partnerships.

Some of the apps were suspended before they had become available to mainstream users. Many were still in their testing phase at the time of suspension, Archibong said.

The company's admissions are likely to reignite calls for heightened regulation of Facebook, while infuriating critics in Congress who believe the social-networking giant has escaped tough punishment for its past privacy abuses. Lawmakers including Sens. Richard Blumenthal, D-Conn., and Josh Hawley, R-Mo., sharply challenged Facebook chief Mark Zuckerberg over his company's data collection practices during private meetings in Washington this week.

The Federal Trade Commission in July issued a record-breaking $5 billion fine and other penalties against Facebook for a series of privacy scandals, including its missteps related to Cambridge Analytica. The political consultancy improperly accessed names, "likes" and other data from millions of the social site's users through a quiz app that collected data on users and their friends, sparking an international outcry. The incident prompted Facebook to conduct a full audit of third-party developers on its platform.

The settlement ending the probe required Facebook to submit to unprecedented government oversight of its privacy practices, while policing third-party apps more aggressively. But critics, including the FTC's Democratic commissioners, argued that it failed to hold Facebook fully accountable and did little to change the company's data collection practices.

The FTC did not immediately respond to a request for comment.

Facebook's decision to release more information about the apps it suspended coincided with a legal war between the tech giant and the attorney general of Massachusetts, which has been investigating the social-networking company for more than a year. Facebook moved to seal a petition by the state that included some details about its app investigation, according to court filings by the company.

Facebook did not name the apps or developers. In May, the company sued the South Korean analytics firm Rankwave, saying the company had offered dozens of apps to people and businesses but had refused to cooperate in Facebook’s investigation.