KUNMING — Law-enforcement officers from China, Laos, Myanmar and Thailand ended the 100th Mekong River joint patrol on Dec 11.

A welcoming ceremony was held at a port in the prefecture of Xishuangbanna, Southwest China's Yunnan province, as four vessels from the Chinese side returned at 4 pm on Dec 11, according to the provincial public security department.

More than 200 officers from the four countries attended the patrol on a total of eight vessels. The trip, covering more than 620 km, took four days and three nights.

A series of activities were held in the four countries to celebrate the 100th joint patrol, including a water-land drill, with communication conducted via video link.

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

The Mekong River, with its Chinese stretch known as the Lancang River, is a vital waterway for cross-border shipping between China, Laos, Myanmar, Thailand, Cambodia, and Vietnam.