FILE - South Korean soldiers take part in an anti-terror drill in Seoul, Aug. 18, 2014.
FILE - South Korean soldiers take part in an anti-terror drill in Seoul, Aug. 18, 2014.

SEOUL - Two South Korean soldiers have died after apparent suffocation during training to withstand capture by an enemy, a military official said, in the latest mishap to hit armed forces already battling charges of physical abuse and lax oversight.

The two career soldiers, who were staff sergeants in a special forces unit, died late on Tuesday during endurance training during which they spent more than an hour with hoods over their heads and hands tied behind them, the official said.

The exact cause of death was being investigated but witness accounts indicate the two soldiers suffocated, the official said, requesting anonymity because he was not formally authorized to speak to the media.

A third soldier was treated at a hospital and has regained consciousness, the official added. Ten soldiers were participating in the exercise recently adopted from a foreign country's military, he said.

Military commanders have pledged to reform the armed forces and the treatment of conscripts who serve mandatory two-year terms to dispel criticism after a series of deadly incidents.

The most recent outcry centered on continuing physical and emotional abuse that led to the death of a conscript soldier in April, in a case that shocked the country.

This week, the military upgraded to homicide the charges against four soldiers facing a court-martial after a human rights group exposed details of the case in July.

In June, a disgruntled conscript in a frontline unit went on a shooting spree, killing five soldiers and injuring seven, raising questions about the military's supervision of soldiers with personal or emotional problems.

The South Korean military has about 630,000 active duty soldiers, many of them conscripts, aimed at deterring aggression by North Korea, which is one of the world's most militarized states.

North and South Korea have been technically at war since their 1950-53 conflict ended in a truce, not a peace treaty.