South Korean military investigators charged two Air Force pilots on Thursday with criminal negligence over an accidental bombing of a village last week during a training exercise, which injured at least 29 people and caused extensive property damage.

Defence ministry investigators have confirmed that errors by the pilots when they entered coordinates into the aircraft systems were "direct factors" behind the accidental bombing, the ministry's Criminal Investigation Command said in a statement.

The pilots were charged with criminal negligence causing bodily harm, the command said, adding the investigation of the incident is ongoing.

Eight unguided air-to-surface bombs were launched from two fighter jets and landed on a village in Pocheon near the border with North Korea during live-fire exercises.

Several areas in Pocheon and neighbouring regions have training grounds used by the South Korean and U.S. militaries.

Residents have for years complained about potential safety risks and disturbance from military units being mobilised in the area.

The two pilots have been taken off flight duties and a review of their flight mission certification has been scheduled, a ministry official said.

The Air Force chief of staff has apologised for the accident and pledged to review mission procedures to prevent similar incidents.

North Korea, which routinely denounces military drills by the South Korean and U.S. militaries, has said the accident showed the risk of the drills triggering armed conflict, citing the possibility the bombs could have dropped north of the border.