(CNN)North Korea fired a shell toward South Korea on Thursday, an official with the South Korean Defense Ministry told CNN.
The claimed military action happened on the western front of the country.
The explosions just hundreds of meters into the South’s portion of the inter-Korean Demilitarized Zone left two soldiers in need of leg amputations.
“Our military in response launched dozens of rounds of 155mm shells towards the site from which the North Korean military launched the rocket artillery”, the ministry said in a statement.
The Yonyap news agency in South Korea said there was no apparent damage.
On that occasion, South Korea responded by shelling North Korean positions, triggering brief fears of a full-scale conflict.
Relations between North and South have been strained after Seoul accused Pyongyang of planting landmines that exploded earlier this month, wounding two South Korean soldiers.
The North responded by putting up its own speakers, broadcasting derogatory remarks about South Korea and lauding the superiority of its communist system.
Seoul then began blasting anti-North Korean propaganda from loudspeakers on the border, resuming a tactic that both sides had halted in 2004.
Tensions routinely flare up between the two Koreas, separated by a heavily fortified de-militarised zone.
“Our military has stepped up monitoring and is closely watching North Korean military movements” Reuters reported the South Korean defence ministry as saying in a statement.