XISHUANGBANNA - A Chinese commercial vessel was attacked by unidentified gunmen Saturday evening on the Mekong River in Laos, sources with a joint patrol command said on Sunday.

The Shengtai-11 was returning from Thailand to Guanlei Port in Xishuangbanna prefecture of southwest China's Yunnan Province when it encountered gunfire. None of its crew were injured.

The attack occurred on a section of the Mekong River that runs through Laos. The river is a major regional transportation route shared by China, Laos, Myanmar and Thailand.

Laos police arrived on the scene by land to search for the suspects, while police forces from China and Laos used a Chinese patrol vessel to arrive at the scene and handle the situation.

Chinese police on Saturday started a second joint patrol with their counterparts from Laos, Myanmar and Thailand in order to maintain security along the Mekong River.

International transport on the Mekong River fully resumed after the four nations' law enforcement agencies conducted a joint patrol on December 10 and stepped up cooperation to ensure the safety of the river.

Passenger services on the river were suspended for four months after tourists were robbed in the river's "Golden Triangle" area in August. Shipping services were also halted after 13 Chinese sailors on two cargo ships were killed in the area on October 5.