WUHAN — Hubei province, the center of the novel coronavirus outbreak in Central China, announced on March 10 it will adopt a differentiated personnel control policy, allowing healthy people from medium- and low-risk areas to travel within the province.

Via a mobile app, each resident of the province will be granted a colored QR health code. A red code indicates the holder is a confirmed or suspected COVID-19 case, a yellow one indicates a close contact, while a green one means the holder has no contact with any cases.

The green code holders from the medium- and low-risk areas will be given green light across the province to promote operation resumption of enterprises while ensuring the safety of the personnel, according to a circular issued by the provincial COVID-19 control headquarters. The green code holders from high-risk areas should follow the specific travel rules of local authorities.

The yellow code holders will not be allowed to travel and those carrying red codes must be quarantined and treated, said the headquarters.

The colors of the health codes may switch based on the health conditions of the holders.

The province has previously classified its cities and counties based on the risks of the epidemic. Cities, counties and districts with no newly confirmed cases in the last 14 days are categorized as low-risk regions, those with fewer than 50 cases or those with over 50 but without a concentrated outbreak are classified as medium-risk regions, and those with over 50 cases as well as a concentrated outbreak are classified as high-risk regions.

By the end of March 6, 19 cities and counties had been classified as high-risk, with 37 as low-risk and 20 as medium-risk.

As of March 9, Hubei had seen no new confirmed COVID-19 cases for five consecutive days in its 16 cities and prefectures outside its provincial capital of Wuhan, the epicenter of the outbreak.