A North Korean fighter jet crossed briefly into South Korean air space Thursday, the first such incident in 20 years. The incursion is the latest provocative step taken by North Korea in the international dispute over its nuclear programs.
The MiG-19 jet flew over a maritime border separating North and South Korea for just a few moments Thursday morning, then retreated back into North Korean territory. South Korea quickly activated an anti-aircraft unit near the key port city of Incheon and sent fighter jets up to patrol the area.
The incursion, the first since 1983, comes just two days after North Korea said it might pull out of the armistice that ended the Korean War, 50 years ago.
South Korea has protested the incident and says it is investigating. Officials in Seoul warned North Korea to avoid further incursions.
Tensions have been mounting on the Korean Peninsula since October, when the United States said North Korea admitted to having a secret nuclear weapons program, in violation of a 1994 agreement. Over the past few months, North Korea has withdrawn from a global non-proliferation treaty and moved to restart idled nuclear facilities at Yongbyon that could produce fuel for nuclear weapons.
The motive for the flight is not known. Analysts noted it could be an accident. However, North Korea has long said it does not recognize the maritime border, known as the Northern Limit Line. Last June, North Korean fishing and navy boats crossed the line, resulting in a battle with South Korean forces that killed six South Korean sailors and several North Koreans.
Park Yong-ok, a retired South Korean army general and professor at Seoul's National Defense University, says whatever the motive, the flight could further damage Pyongyang's relations with Seoul. "If they repeat that kind of thing, that is likely to endanger the current status of the inter-Korean reconciliation process," he says.
For months, Pyongyang has dished out daily accusations that the United States is planning to attack it, a charge Washington has denied repeatedly.
North Korea has warned that it will strike at South Korea if it feels threatened. North Korea demands that the United States sign a non-aggression pact to resolve the current dispute. Washington rules out a pact but says it is willing to talk, although it wants to include South Korea in any discussions.
The incursion follows reports in the United States and South Korea that more activity has been seen at the North's Yongbyon nuclear facility. It is not clear, however, if the activity indicates the plant is fully back in operation or if Pyongyang is actually starting to process plutonium for weapons.
The United States, South Korea, China, Japan and Russia have all opposed any nuclear weapons on the Korean Peninsula. Washington says that in addition to threatening the region's security, Pyongyang could sell any nuclear weapons it builds to other countries or terrorist organizations.