Fire was exchanged across the border between North and South Korea on Sunday, the second time skirmishes erupted in the past 10 days.
Reports indicate that North Korean troops approached the border in response to a leafleting campaign by the South, after which southern troops opened fire.
The first border clash on October 10, came after North Korean soldiers fired at balloons released from across the border, carrying leaflets critical of Kim Jong-un.
Last week officials from both countries met for the first time in three years in an attempt to ease tensions, however the talks ended without any agreement.