KUNMING - The 28th round of joint patrols on the Mekong River in the Golden Triangle region kicked off on Tuesday morning, guarding the waterway against criminal activity.

The four-day patrol by China, Laos, Myanmar and Thailand involves four law enforcement ships from China, one from Laos and officers from the four countries, according to the border defense force in Southwest China's Yunnan province.

Law enforcement personnel from the four countries will carry out checks and drills to prevent crime such as drug, gun and human smuggling. They will also exchange information in terms of navigation and agricultural production.

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

The past 27 patrols have seen 1,633 personnel, 21,400 tonnes of cargo and 301 ships checked by police officers.