KUNMING, Dec. 21 (Xinhua) -- The 77th Mekong River joint patrol led by China, Laos, Myanmar and Thailand concluded Friday at Guanlei Port, Xishuangbanna Dai Autonomous Prefecture in southwest China's Yunnan Province.

Six vessels and 126 law enforcement officials from the four countries participated in the mission, which covered a range of more than 500 km in four days.

A total of 13 vehicles, 32 people and 20 tonnes of cargo were inspected during the mission, along with anti-terrorism drills, police skill practices and an anti-drug campaign.

An information exchange meeting was held in Chiang Saen, Thailand.

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, 2011.

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