A ceremony marking the start of construction of a high-speed railway between Shenzhen and Jiangmen of Guangdong province is held on Oct 9, 2022. [Photo by Tan Liang/For chinadaily.com.cn]

Construction of a high-speed railway between Shenzhen and Jiangmen, Guangdong province, started on Sunday, according to the China State Railway Group Co Ltd.

The 116-kilometers railway, part of the high-speed railway network in China's coastal areas, begins at the Xili station in Shenzhen, passing west through Dongguan, Guangzhou, Zhongshan and Jiangmen cities, and connects another line to Zhanjiang at the Jiangmen station.

It will take five and a half years to complete the construction of the Shenzhen-Jiangmen railway, given that up to 98 percent of the line will be bridges and tunnels, the China State Railway Group said.

A 13.69-km tunnel at the mouth of the Pearl River, which will be as deep as 106 meters under sea level, will be a key project during construction of the line, the railway group said.

The Shenzhen-Jiangmen line will also connect a high-speed railway between Shenzhen and Xiamen in East China's Fujian province, helping further facilitate travels for people in the Guangdong-Hong Kong-Macao Greater Bay Area.