Apple has removed some applications from its App Store after developers in China were tricked into using software tools that added malicious code in an unusual security breach.

Apple gave no details of which companies were affected. But Tencent said its popular WeChat app was affected and the company released a new version after spotting the malicious code.

Chinese news reports said others affected included banks, an airline and a popular music service.

The malicious code spread through a counterfeit version of Apple's Xcode tools used to create apps for its iPhones and iPads, according to the company.

It said the counterfeit tools spread when developers obtained them from "untrusted sources" rather than directly from the company.