The service wasorganised annually by the provincial authorities on the 15th and 16thdays of the third Lunar month, which fell on May 3 and 4 this year.
Some 3,157 local people, including children, women and elderlypeople, were slaughtered when the Khmer Rouge forces entered Ba Chuccommune from April 18-29, 1978.
To remember the victims of the massacre, the local authorities built a tomb to keep the remains of 1,159 victims.
The Ba Chuc tomb was recognised as the national historical relic site in 1980.
Upgrades to the 5-hectare tomb started in 2011 with a totalinvestment of 30 billion VND (1.39 million USD) and are expected to befinished by 2018 to mark 40 years since the massacre.-VNA