SEOUL, Nov. 22 (Yonhap) -- North Korea threatened on Thursday to launch bomb attack on South Korean soil as Seoul prepares to hold events marking the second anniversary of the North's deadly shelling of a South border island two years ago.

A memorial service, a naval firing drill and other commemorative events are to take place to commemorate the deaths of two soldiers in the North's artillery bombardment of Yeonpyeong Island in the Yellow Sea on Nov. 23, 2010. The attack, which was the first launched by the North against civilians in the South since the Korean War ended in a truce in 1953, killed two soldiers and two civilians.