The enforcement vessel from China, which is participating in the 88th Mekong River joint patrol, pulls out Guanlei Port in southwest China's Yunnan Province, Nov. 19, 2019. (Xinhua/Wu Han)

Law-enforcement authorities from China, Laos, Myanmar and Thailand joined forces on Tuesday to start the 116th Mekong River joint patrol.Three Chinese vessels departed at 9 a.m. from Jingha Port, Xishuangbanna Dai Autonomous Prefecture, southwest China's Yunnan Province, according to the provincial public security bureau.During the four-day patrol, the four countries will carry out non-contact operations to safeguard safety and stability along the river basin.The Mekong River, known as the Lancang River in China, is a vital waterway for cross-border shipping.China, Laos, Myanmar and Thailand have been conducting joint patrols on the river dating back to December 2011.