The cargo ships arrived under the first joint-patrol operation of China, Thailand, Laos and Burma, following the murder of 13 Chinese sailors on two cargo ships on October 5.

Cargo shipments stopped sailing on a section of the Mekong River in the Golden Triangle area where Laos, Burma and Thailand's borders meet after the 13 Chinese sailors were murdered.

Xinhua reported on Monday that the cargo ships departed on Saturday from Yunnan Province escorted by five patrol vessels. When they entered the section of the Mekong River on the Laos-Thailand border, a fleet of 10 Thai patrol vessels loaded with armed officers and heavy machines guns waited to escort them to their destination. An armed helicopter hovered in the sky.

Meanwhile, on Sunday, when the Chinese cargo ships arrived at Chiang Saen port, three Burmese soldiers were killed in a clash with an armed group led by Sai Naung Hkam on the Mekong River during a joint patrol by Burma and Laos, the Bangkok Post, a Thailand-based newspaper reported on Monday.

According to the newspaper, the joint patrol force of Burmese and Lao soldiers fought the armed group at the location where the 13 Chinese sailors were killed, located about 20 kilometres north of the Golden Triangle.

A resident in Tachileik, Burma, said that the clash broke out between the Tachileik-based Light Infantry Unit No. 526 and the armed group at Sanhpoo village in Wanpon Township about 24 kilometres northeast of Tachileik. He also said that there was a bomb blast on Sunday night.

“I heard they fought with armed drug traffickers. It’s not appropriate to ask about it in detail because it involves the armed forces,” he said.

Major Sai Lao Hseng, the spokesman of the Shan State Army-South (SSA-S), said the government’s Kengtung-based Triangle Region Command on Saturday asked the SSA-S whether its troops were in the area.

“They are trying to combat an unknown armed group. They told us about it, because they were afraid that they would mistakenly attack us,” Major Sai Lao Hseng said.

After the earlier attack on the two Chinese cargo ships, the authorities said they found a total of 920,000 amphetamine pills on the ships where the 13 Chinese sailors were killed; 520,000 pills on the cargo ship “Hua Ping,” and 400,000 pills on the cargo ship “Yu Xing 8 Hao.”

Thailand’s Pa Muang Task Force said Sai Naung Hkam led the armed drug group responsible for the attack on the Chinese sailors, but later Thai police arrested nine soldiers from the Pa Muang Task Force for being involved in the case and charged them with murder.

Police Major General Sitthiporn Srichanthap, the deputy chief of the Police Region 5, told the Bangkok Post on Sunday said the case against the nine Thai soldiers has been submitted to the Office of the Attorney General.

Sai Naung Hkam, a former officer in the now defunct Mong Tai Army, led by the late Burmese drug lord Khun Sa, who had a close relationship with former Burmese junta military officers, lived in Tachileik when Khun Sa surrendered to the former junta. Several million amphetamine pills and weapons were found at his home in 2006. Residents and observers say that he extorts money from cargo ships running on the Mekong River.

On October 31, a four-country meeting between China, Laos, Thailand and Burma was held in Beijing, in which it was agreed to conduct joint law enforcement along the Mekong River. Burma’s Home Minister Lieutenant General Ko Ko attended the meeting.

The five patrol vessels that escorted the 10 cargo ships are equipped with heavy machine guns and 10cm protective shields, and police officers carry automatic rifles and bullet-proof life jackets, according to the Xinhua news agency.