Messaging app Telegram and newly released Telegram X are back in the App Store after being pulled by Apple, reports ZDNet. 

The apps disappeared at midnight CET, and soon afterward Telegram CEO Pavel Durov tweeted that Apple had removed them because of "inappropriate content," adding, "Once we have protections in place we expect the apps to be back on the App Store." 

Durov later tweeted confirmation of the apps' return.  

Telegram X is a faster alternative to Telegram and includes themes and more efficient battery use. Both Telegram and Telegram X remained available on Google Play.

Telegram's developers say the apps are more secure than other messaging systems because their secret chats use end-to-end encryption, don't leave a trace on servers, block forwarding and support self-destructing messages.

But the apps have also been the target of criticism for allegedly allowing terrorists to communicate. UK Prime Minister Theresa May said in a speech last week that "smaller platforms can quickly become home to criminals and terrorists. We have seen that happen with Telegram. And we need to see more co-operation from smaller platforms like this."

For its part, Telegram says on its website, "While we do block terrorist (e.g. ISIS-related) bots and channels, we will not block anybody who peacefully expresses alternative opinions."  

Apple didn't immediately respond to a request for comment. 

CNET Magazine: Check out a sample of the stories in CNET's newsstand edition.

The Smartest Stuff: Innovators are thinking up new ways to make you, and the things around you, smarter.