North Korea's military has threatened to destroy propaganda facilities such as loudspeakers South Korea has placed along their border.
North Korean state-run media broadcast the statement Saturday, the North's latest threat since South Korea blamed the deadly March sinking of one of its warships on North Korea.
After the incident, South Korea set up loudspeakers to broadcast anti-North Korean propaganda in 11 places along their demilitarized border. North Korea's military said Saturday it will blow up the facilities, and threatened to turn the South Korean capital Seoul into what Pyongyang called a "sea of flame."
South Korea's Yonhap news agency quoted the South Korean Joint Chiefs of Staff as saying no unusual activity has been observed along the border.
Last week, Seoul formally asked the U.N. Security Council to punish North Korea for a torpedo attack on South Korea's Cheonan warship, in which 46 sailors were killed. An international investigation blamed the attack on a North Korean submarine.
Some information for this report was provided by AFP, AP and Reuters.