North Korean soldiers (file)
North Korean soldiers (file)Reuters

South Korea on Friday said it returned artillery fire after being shelled by its northern neighbor, reports the South Korean Yonhap News Agency.

Apparently the clash came as South Korean activists launched balloons condemning North Korean dictator Kim Jong-Un, after North Korea threatened "catastrophic" consequences if the activists weren't stopped.

This is not the first time North Korea has attacked South Korea in recent times, although a clash on land and not sea is rare; in late March an exchange of fire occurred after a North Korean maritime drill strayed into South Korean waters. 

The fighting comes after Pyongyang's second most powerful man, Hwang Pyong-So, made a rare visit to Seoul on Saturday accompanied by other officials. Reportedly Hwang had asked to deliver a "heartfelt greeting" from Kim to South Korean President Park Geun-Hye.

The clash also coincides with increasing speculation that Kim is seriously ill, as he missed a key anniversary of his Workers' Party on Friday for the first time since taking power in 2011.

Rumors have abounded that Kim, who has been out of the public eye since September 3, is suffering from gout, with yet other rumors speculating that he has been the subject of a military coup.

Kim has in the past threatened nuclear war on his southern neighbor and Japan. He has often threatened war, such as last December when he put his army on notice for imminent combat.

At the time he said "we must greatly hurry preparations for battle, not forgetting that war is not the kind of thing that you advertise when you'll do it."