Shipping in the region is safer than ever thanks to joint efforts between China and its three neighbors, reports Hu Yongqi in the Golden Triangle

Sirens blared a warning across the apparently tranquil Mekong River as a Chinese patrol fleet entered the waters of the Golden Triangle, Asia's second-largest opium-producing region.

Chinese border police loaded their guns in the cabin before jumping through a hatch onto the deck in response to the Level 1 alert. The area is notoriously dangerous and was formerly the hunting ground of a gang led by Naw Kham, a Myanmar drug lord who was executed in March in Kunming, the capital of Yunnan province.

The Chinese officers, who are stationed in Xishuangbanna Dai autonomous prefecture in Yunnan, were ordered to take cover behind bullet and shellproof panels.

Ji Guojun, a 26-year-old officer, took up position on a platform at the stern of the ship. Another officer in full body armor stood on the bow and surveyed the surroundings through binoculars. Near at hand, he kept a machine gun whose 6-cm-long cartridges have a range of 2 kilometers. However, there was nothing to see and the only sounds came from the water rushing by under the ship.

The officers heaved a collective sigh of relief, but it was the tensest moment of the 16th joint river patrol by forces from China, Laos, Thailand and Myanmar. Yunnan Border Police Corps, a subdivision of the Ministry of Public Security, sent three ships and more than 100 armed officers to assess safety on the river.

The patrol followed its usual route on the 512-km round trip, which started at Guanlei in Xishuangbanna on Nov 19 and ended at the port of Chiang Saen in Thailand four days later.

The Mekong flows through six countries, including China, Myanmar, Laos and Thailand, and is a vital channel for cargo shipping.

However, international shipping was temporarily suspended in the Golden Triangle in October 2011, after 13 Chinese fishermen were kidnapped and murdered by Naw Kham's gang. The drug lord was executed in March.

More than one month after the attack, Chinese police initiated the joint patrols to maintain safety on the river. Then the Yunnan Border Police launched a new unit, called the Waters Division, to patrol the river and improve communications with China's three neighbors, said Jin Shangwen, chief of staff of the Yunnan Border Police Corps, who also commanded the 16th Patrol Fleet.