KUNMING, Aug. 23  -- The 85th Mekong River joint patrol led by China, Laos, Myanmar and Thailand concluded Friday, as two Chinese law enforcement boats anchored at Guanlei Port, Xishuangbanna Dai Autonomous Prefecture in southwest China's Yunnan Province.

More than 140 law enforcement officers from the four countries, in seven vessels, participated in the four-day mission, according to the Yunnan provincial public security department.

A total of 17 vehicles, 26 people and 1.35 tonnes of cargo were inspected during the mission.

The four sides exchanged opinions and reached agreement on joint patrol in September, multilateral information exchange and cultural exchange activities.

The joint patrols started in December 2011 after a gang hijacked two cargo ships and killed 13 Chinese sailors in Thai waters on Oct. 5 that year.

The Mekong River, known as the Lancang River in China, is a vital waterway for cross-border shipping among China, Laos, Myanmar, Thailand, Cambodia and Vietnam.