Law enforcement authorities from China, Laos, Myanmar and Thailand launched their 155th joint patrol of the Mekong River on Tuesday to combat cross-border crimes.

The operation began at approximately 9 a.m. Tuesday, when three Chinese law enforcement vessels departed from the Jingha port in southwest China's Yunnan Province, marking the official start of the joint patrol. Lao and Myanmar patrol boats left the Muang Mo port in Laos and the Wan Pong port in Myanmar simultaneously, bound for a pre-determined area.

Over 100 law enforcement personnel from China, Laos, Myanmar and Thailand as well as seven patrol vessels from China, Laos and Myanmar are participating in the joint patrol, which is expected to last four days and three nights. The mission will include joint land-water inspections and training in key water areas like Ban Xiangkok, targeting drug trafficking, fraud, smuggling and illegal immigration.

During the patrol, relevant law enforcement agencies from the four countries will hold an information exchange meeting in Chiang Saen, Thailand, to analyze the security situation in the Lancang-Mekong drainage area, discuss case information and plan future cooperation priorities.

The previous joint patrol concluded in late June, seeing a law enforcement fleet carry out diverse drug-prevention campaigns in riverside villages, schools and enterprises, and distribute over 1,000 drug education leaflets and 4,000 educational items.

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.