Twitter will begin removing tens of millions of suspicious accounts from users’ followers on Thursday, signaling a major new effort to restore trust on the popular but embattled platform.

The reform takes aim at a pervasive form of social media fraud. Many users have inflated their followers on Twitter or other services with automated or fake accounts, buying the appearance of social influence to bolster their political activism, business endeavors or entertainment careers.

Twitter’s decision will have an immediate impact: Beginning on Thursday, many users, including those who have bought fake followers and any others who are followed by suspicious accounts, will see their follower numbers fall. While Twitter declined to provide an exact number of affected users, the company said it would strip tens of millions of questionable accounts from users’ followers. The move would reduce the total combined follower count on Twitter by about 6 percent — a substantial drop.

An investigation by The New York Times in January demonstrated that just one small Florida company sold fake followers and other social media engagement to hundreds of thousands of users around the world, including politicians, models, actors and authors. The revelations prompted investigations in at least two states and calls in Congress for intervention by the Federal Trade Commission. In interviews this week, Twitter executives said that The Times’s reporting pushed them to look more closely at steps the company could take to clamp down on the market for fakes, which is fueled in part by the growing political and commercial value of a widely followed Twitter account.