The 85th Mekong River joint patrol led by China, Laos, Myanmar and Thailand started Tuesday from Jingha Port in southwest China's Yunnan Province.

The patrol, expected to last four days and three nights, will involve inspections, a crackdown on drug crime and an anti-drug publicity campaign, according to the provincial public security department.

The mission will cover key waters including the "Golden Triangle," an area notorious for drug production.

The joint patrol program 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.