KUNMING, Oct. 21 (Xinhua) -- A tunnel along the railway connecting China and Laos was completed Monday, said China Railway's Kunming bureau.

The Manzhang Tunnel, located in Mengla County, Xishuangbanna Dai Autonomous Prefecture, southwest China's Yunnan Province, is 1,730 meters long.

Started in September 2016, construction of the tunnel went smoothly despite collapses, landslides and other geological difficulties.

The China-Laos railway is more than 1,000 km long, which links Kunming, capital of Yunnan, and Vientiane. It is expected to open by the end of 2021 and will slash the travel time between the two cities to half a day.