Thirty provinces, municipalities and autonomous regions in China have activated the Level-I alert of public health incidents, the highest level of emergency public health alerts and responses in the nation's public health management system.

Inner Mongolia autonomous region announced a Level-I alert on Saturday evening, making itself the latest provincial-level area that has launched the top-level emergency mechanism.

Zhejiang in East China was the first to announce such move on Thursday morning, followed by Guangdong in South China and Hunan in Central China on the same day.

China's public health alert system is categorized into four levels in terms of the incidents' nature, extent of harm and scope: Level-I (Extremely significant), Level-II (Significant), Level-III (Major) and Level-IV (Normal).

Under the Level-I alarm, the provincial government is responsible for organizing, coordinating and handling all the emergency public health treatments, information disclosure, and gathering emergency materials and facilities, under the guidance of the State Council.