Apple said on Thursday that it had removed some applications from its App Store, expressing its concern that the security of some users' personal data. The company said the apps threatened users' security by installing certificates that can expose data to monitoring by third parties. The company did not specify the precise number of apps at issue.

"Apple is deeply committed to protecting customer privacy and security," an Apple spokeswoman said in a statement. "We are working closely with these developers to quickly get their apps back on the App Store, while ensuring customer privacy and security is not at risk."

Among the apps removed was Been Choice, which has attracted attention for its ability to block advertising in apps.