Nguyen Hoang Nhut, 39, who taught biology at Duong Minh Chau Secondary School, was charged with "engaging in sexual intercourse or other sexual activities with a person aged 14 to under 16" and "molestation of a person under 16."

Nhut was also required to pay VND10 million ($433.16) in damages to each of the three victims, with the fourth declining compensation.

According to the indictment, the teacher had joined an LGBT social media community in June 2019, noticing one of his male students was also a member. He first approached the student by asking him to clean the school lab, where he engaged the victim in oral sex.

A week later, Nhut called the student to his house where they engaged in sexual intercourse.

Investigators identified three other male students whom Nhut had coerced into sexual misconduct.

The incident came to light last year after one of the victims' family filed a police complaint.

Recent reports of male teachers sexually assaulting school students have shocked the nation.

In October 2019, a former principal of a boarding school in northern Phu Tho Province was sentenced to eight years in prison for sexually abusing nine male students for years.

Official data shows more than 8,000 Vietnamese children have been sexually or physically assaulted since 2015. In most cases, perpetrators have been found to be those familiar with the children, such as teachers, relatives and neighbors.