The drowning occurred at around 3 p.m. after a group of 10 students from the northern province’s Huu Nghi Primary and Secondary School went for a swim in the Da River.
It is said that after they fell into a deep water hole, only two managed to swim to the shore.
The bodies of the eight children were recovered at around 4:30 p.m. Three primary school students were among the dead. They were seen playing football on the banks before jumping into the river.
"The river has a deep water hole and the students might have been from neighboring places who did not know this," a local official said.
Drowning is one of the main causes of child deaths in the country. According to a recent survey by the World Health Organization, more than 11,000 children drown each year in Vietnam.
Speaking on this issue, experts had said at a seminar last year that a lack of facilities and personnel to teach children swimming and safe behavior was made worse by a lack of knowledge and awareness among parents and other relatives.
Bloomberg Philanthropies (BP) had last year announced a $2.4 million donation to fund the first two years of a five year program to prevent drowning deaths among children in Vietnam.
Last month, five ninth grade students in the central province of Quang Nam died after going swimming in a local beach.