朝鲜誓言严厉报复首尔举行的抗议平壤活动

North Korea has issued fresh threats against South Korea, vowing retaliation for recent protests in Seoul that it says "hurt the dignity" of the leadership in Pyongyang.

The North's military threatened unspecified "immediate" action against the South if it did not apologize for the small Monday protests, during which effigies of North Korean leaders were burned.

The statement, read on state television Tuesday, included typically inflammatory language, vowing "sledge-hammer" revenge for what it said was the protesters' "monstrous criminal act."

The threat comes as North Koreans continue their two-day celebration of the birthday of late founding leader Kim Il Sung. Many had expected Pyongyang to mark the occasion with a provocative missile test, but the Monday anniversary passed without incident.