Hundreds have turned out for a protest in Seoul, condemning the attack from North Korea and demanding a tough response from the South Korean government.
North Korean flags were burned, and so too were photos of communist leader Kim Jong-il and his son and predecessor Kim Jong-un.
One man in Seoul said: “It’s very overwhelming, and the South Korean people were really surprised, me included. So it’s true that we’re worried that war might break out.”
North Korean media do not appear to have reported the deaths and casualties in the South.
One man in Pyongyang said: “The South Korean puppets should know that our army responds to any provocative fire with a merciless shower of fire.”
Another resident said: “I think this time the Korean People’s Army demonstrated to the world that it doesn’t make empty talk.”
Officials in Pyongyang have refused to give information to the foreign press to back up its claims that South Korea fired towards the North.