The world's first high-speed railway operating in extremely low temperatures will begin service on April 21 that can reach speeds of up to 300 kilometers per hour.

The 921-km line linking Harbin, capital of China's northernmost province of Heilongjiang, and the port city of Dalian, Liaoning province, currently operates at 200 km per hour based on its winter schedule.

Since the line opened on Dec 1, it has withstood tests of extremely low temperatures and inclement weather and proved safe and reliable, said Gao Wen, deputy director of Shenyang Railway Bureau, which manages the line.