Workers construct a tunnel, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province, May 26, 2020. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

A worker is seen at the construction site of a tunnel, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province, May 26, 2020. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

Photo taken on May 26, 2020 shows the entrance of a tunnel under construction, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

Workers construct a tunnel, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province, May 26, 2020. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

Aerial photo taken on May 26, 2020 shows the entrance of a tunnel under construction, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

Workers construct a tunnel, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province, May 26, 2020. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)

Aerial photo taken on May 26, 2020 shows the entrance of a tunnel under construction, which is part of the south section of the extension line of North Gongye Road, in Fuzhou, southeast China's Fujian Province. The construction of the south section of the extension line of North Gongye Road in Fuzhou has entered the tunnelling phase under strict COVID-19 pandemic prevention and control measures. The project is expected to be completed by September 2021. (Xinhua/Jiang Kehong)