KUNMING, June 20 -- A new round of joint patrols on the Mekong River with law enforcers from China, Laos, Myanmar and Thailand, started from a Chinese port Tuesday.

Eight ships and 204 law enforcers participated in the 59th mission since 2011. The ships set sail from Guanlei Port in Xishuangbanna, southwest China's Yunnan Province, and will travel over 500 kilometers.

During the new joint patrol, law enforcers will carry out anti-narcotics propaganda and review the current narcotics situation and crackdown.

The patrol came ahead of the International Day against Drug Abuse and Illicit Trafficking on June 26.

The joint patrols started in December 2011 to tackle safety concerns after a gang hijacked two cargo ships and killed 13 Chinese sailors in Thai waters on Oct. 5, 2011.