Duolingo Inc (DUOL.O) said late on Thursday it was aware that its popular Duolingo language learning app was no longer available for download on some app stores in China.

Its removal from the Chinese app stores comes after Beijing last month issued rules barring curriculum-based tutoring for profit and barred foreign investment in the sector, dealing a blow to the country's $120 billion private tutoring industry.

Duolingo could not be downloaded on Android app stores operated by companies such as Huawei Technologies (HWT.UL) and Tencent Holdings (0700.HK) as of Friday. It was still available on Apple Inc's (AAPL.O) Chinese app store.

"We are working to address the issue and are hopeful that the app will be reinstated in the near term," Pittsburgh-based Duolingo said. "In the meanwhile, existing users in China can continue to use the app as they always do."

Huawei and Tencent did not immediately respond to requests for comment. The Duolingo app is free to download and allows users to learn more than 30 languages.

TikTok owner ByteDance told employees on Thursday it planned to lay off staff in its education business and close some of its tutoring operations, including its one-on-one English online classes app Gogokid.