The explosion, which took place at around 9.50am occurred “during a grenade throwing training” at a military unit in South Chungcheong Province, around 100km south of the capital Seoul, the ministry said in a statement.

The unit quickly transported the two injured men to a military hospital but “the trainee died,” the statement said, adding that “the officer is currently receiving emergency treatment and is conscious.”

The military “sincerely conveys its deepest condolences to the family of the deceased soldier” and plans to “investigate the precise cause of the accident in cooperation with civilian police,” it added.

All able-bodied South Korean men under the age of 30 must perform about two years of military service, mainly because the country remains technically at war with nuclear-armed Pyongyang.

The South Korean military relies heavily on conscription and the mandatory service often involves postings to front-line positions on the border with North Korea.

For many young South Koreans, the policy of conscription is an unwanted and deeply resented intrusion that interferes with studies or nascent careers, especially in a rapidly ageing society where the size of the workforce is dwindling by the year.

The death of conscripts on duty is sensitive for the government and military, with the case of a marine who died last year during floor relief work recently becoming politically charged, ahead of April legislative elections.

A series of shooting incidents took place in the mid-2010s involving suicides and reservists turning their guns on other members of their unit.