KUNMING, Nov. 25 (Xinhua) -- Two Chinese law enforcement vessels returned to port in southwest China's Yunnan Province on Friday, concluding the 123rd joint Mekong River patrol by China, Laos, Myanmar and Thailand.

(File photo: CGTN)

Four vessels from the countries traveled over 600 km for four days and three nights, working to deter crime and ensure the safety and stability of the river basin, according to the Yunnan provincial public security department.

A total of 84 law enforcement officers were aboard the vessels.

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 of the river since December 2011.