Apple has reportedly begun cracking down on another type of application in China following the removal of VPN (virtual private network) services from the App Store last year.

In its latest Far East Asian purge, Apple has begun removing apps that use the CallKit framework, according to 9to5Mac. The CallKit, introduced in iOS 10, enables developers to integrate calling services with other call-related apps.

The move from Apple is in response to newly enforced government regulations which take issue with the VoIP (voice over internet protocol) functionalities of the CallKit.

The tech giant has been notifying developers that have the CallKit integration in China that they must either remove the integration or remove their app from China entirely.

This notification reads: “Recently, the Chinese Ministry of Industry and Information Technology (MIIT) requested that CallKit functionality be deactivated in all apps available on the China App Store.

“During our review, we found that your app currently includes Callkit functionality and has China listed as an available territory in iTunes Connect.”

The ban on apps with VoIP functionalities has been a long time coming in China. The nation’s popular messaging app WeChat supported CallKit for a period but later removed it and Apple was forced to remove the Skype app from China over its VoIP capabilities.