Seoul: North Korea`s rocket exploded mid-air two minute and 15 seconds after blast-off and its debris splashed down in the Yellow Sea off South Korea, Seoul`s Defence Ministry said on Friday.
The rocket, which lifted off at 2238 GMT from Tongchang-ri in the northwestern county of Cholsan, exploded several tens of kilometres south of the launch pad, it said.
"We believe the missile splintered into two parts, probably due to a blast," ministry spokesman Kim Min-Seok told reporters.
"The test is deemed to have failed," he said.
The rocket apparently exploded when it reached an altitude of 70.5 kilometres above the sea and was travelling at 5.6 times the speed of sound.
After the explosion, the two chunks of debris continued flying up southward, reaching as high as 151.4 km and passing over South Korea`s Baengnyeong island near the sea border.
One of the two chunks further disintegrated into some 10 pieces at 22:47:42 GMT and fell over a wide area in the sea off the South`s Taean peninsula.
The other chunk flew further south before breaking up into three pieces and landed in the sea off the southwestern port of Kunsan, the ministry said.
South Korea`s Navy launched a search to salvage the debris in the Yellow Sea, Kim said, adding it would take "quite a lot of time" to find it, Yonhap news agency reported.
Yonhap said more than a dozen South Korean Navy ships, many of them equipped with sonar and backed by divers, were combing the area.
"We believe some large chunks are lying on the sea bed," the spokesman said.
The depth of the sea is between 70 and 100 metres making it feasible to retrieve large chunks of debris. (AFP)