WASHINGTON >> The operator of a video-sharing app popular with teenagers is agreeing to pay $5.7 million to settle federal allegations it illegally collected personal information from children.

The Federal Trade Commission says the Wednesday penalty against lip-syncing app Musical.ly, now known as TikTok, is the largest ever obtained in a children’s privacy case.

The FTC says the app violated the Children’s Online Privacy Protection Act, which requires kid-oriented websites to get parents’ consent before collecting personal information from children under 13.

TikTok says it’s starting a separate, more restrictive app for younger U.S. users.

FTC Chairman Joe Simons says Musical.ly knew many younger children were using the app and collecting names, email addresses and other personal information without parental consent.

Musical.ly merged last year into China-based TikTok.