Naw Kham, the principal suspect in the murders of 13 Chinese sailors on the Mekong River last year, pleaded guilty Friday as he and five other suspects stood trial in Kunming, Yunnan Province.

The trial, which opened Thursday morning at the Intermediate People's Court of Kunming, ended on Friday, one day ahead of schedule.

Naw Kham, head of an armed drug gang from Myanmar, expressed his penitence to the victims and their families in court, hoping for leniency.

The court will pick a date for sentencing following a review of the case by a collegiate bench.

Lawyers of the family members of the 13 Chinese victims asked for death penalties for the six suspects, as well as economic compensation.

The six defendants were also required by the victims' families to make open apologies to the 13 sailors and their families through media.

Naw Kham denied plotting the attack on Thursday.

However, the five other defendants on trial all testified in court that Naw Kham was the gang's ringleader and had masterminded the attack.

The six suspects were charged with intentional homicide, drug trafficking, kidnapping and hijacking by the Kunming People's Procuratorate.

The crime ring was busted earlier this year in a joint operation by police from China, Laos, Myanmar and Thailand after the brutal murders of the Chinese sailors triggered an outcry in China last year.

The 13 Chinese sailors were confirmed dead after two cargo ships, the Hua Ping and Yu Xing 8, were hijacked on October 5, 2011 on the Mekong River.

Police from China, Laos, Myanmar and Thailand began cooperating more frequently in patrols on the Mekong River in the Golden Triangle Region after the murders, in order to secure transportation and target cross-border crimes, according to Chinese police authorities.

They began a new round of joint patrols Friday, the sixth round of its kind since last December.

Patrol fleets from China and Laos will sail along a Laos-managed section of the Mekong River to check ships, said a police officer in charge of China's Yunnan Provincial Border Control Corps.

Police officers will also check key sections on the bank of the river in Laos, added the source, who declined to be named.

Chinese shipping on the river was seriously affected after the two Chinese ships were attacked and hijacked in October last year.

The joint patrols, considered a safeguard against crimes, have resulted in more ships resuming operations.

Statistics showed that only 10 Chinese ships were shipping on the river when the first four-country joint patrol was launched in December last year.

That number increased to 59 when the fifth patrol was conducted in August.

Xinhua