South Korea has confirmed firing dozens of artillery shells in retalliation against an attack by North Korea. The action followed earlier reports that North Korea had fired over 200 rounds across its western maritime border. Witnesses say the shells hit one of South Korea’s islands in the Yellow Sea where over 60 houses are ablaze. Reports say one South Korean marine has been killed and at least 14 people have been injured. Seoul has since placed the country is on its highest non-wartime alert.