BEIJING - China's Foreign Ministry confirmed Sunday that 11 Chinese were killed and two remain missing after their boats were attacked in the Mekong River four days ago.

Two cargo ships, the Hua Ping and Yu Xing 8, were attacked in the golden triangle area of the Mekong River on October 5, the ministry said in a statement on its website.

Among the six Chinese on the Hua Ping, five were found dead and one was missing. Among the seven Chinese on the Yu Xing 8, six were killed and one was missing, according to the statement.

The ministry said it has asked Chinese embassy in Thailand and consulate general in Chiang Mai to investigate the incident immediately and spare no efforts to search for the missing.

It has also asked "relevant countries" to take effective measures to improve the protection of Chinese ships and sailors in the Mekong River, according to the statement.

The ministry said leaders of the Communist Party of China Central Committee and the State Council are paying close attention to the matter.

The ministry urged the "relevant countries" to immediately to look into the incident, determine the truth and bring the criminals to justice as soon as possible.

Chinese diplomats in Chiang Mai have arrived at the site to investigate. The Chinese embassy in Thailand is having close contact with the Thai side to get further information, according to the statement.