Internet giant Tencent's popular messaging app, WeChat, suffered a large-scale technical mishap on Monday morning.
Many users reported that they could not send out messages from 8 am or browse their friends' home pages, or connect to the WeChat's web version.
Users in Guangdong, Zhejiang, Shandong, Heilongjiang and Henan provinces, as well as in Beijing, reported difficulties.
At around 11 am, Tencent issued a statement which said that the optical cable failures were to blame.
WeChat has over 300 million users in the domestic market, and over 70 million users outside China. The app currently comes in 18 different languages, including English.