SEOUL - The Republic of Korea (ROK) says it won't punish the marines who fired at a civilian jetliner they thought was the Democratic People's Republic of Korea (DPRK)'s military aircraft.

A marine spokesman said Sunday that the soldiers were following their training when they shot at the Asiana Airlines flight carrying 119 people from the Chinese city of Chengdu around dawn Friday. The plane was undamaged.

The spokesman refused to identify himself and wouldn't elaborate.

The airline says no one on board was hurt or even aware of the shooting at the time.

Tensions between DPRK and ROK are high. DPRK threatened earlier this month to retaliate for ROK military's use of photos of leader Kim Jong Il's family for shooting practice.