Jeong Joon Hee, a spokesman for Seoul's Unification Ministry, told that Kim Yong Jin, a vice premier in North Korea's cabinet, had been executed
North Korea has been hit by five sets of UN sanctions since it first tested a nuclear device in 2006
South Korea's Defence Ministry didn't immediately respond to a request for comment
South Korean officials said the submarine-launched missile flew about 500 kilometres, the longest distance achieved by the North
The missile flew 500 kilometres towards Japan, marking what analysts called a clear step forward for country's nuclear strike ambitions
North Korea fired a ballistic missile from a submarine into the Sea of Japan, South Korean and US officials said
The country has also conducted a number of submarine-launched ballistic missile tests
The missile, fell into the Sea of Japan some 300 miles off the coast of North Korea
Under the Korean War armistice, the two sides are barred from carrying out any hostile acts within or across the 4-km -wide DMZ
Service also provides access to selected study sources, suggesting it could be used to enhance distance learning
The two-week annual Ulchi Freedom exercise is largely computer-simulated, but still involves around 50,000 Korean and 25,000 US soldiers
Terming it as a grave provocation, North Korea said the drill is an unacceptable challenge and is endangering regional peace
No date was announced for a follow-up meeting of council members or experts, but Bessho said he hopes for council action as soon as possible
The launch came after North Korea test-fired two medium-range Rodong ballistic missiles and one shorter-range Scud missile
Choe was part of a senior North Korean delegation that visited South Korea in October 2014 during the Asian Games
It had already been heavily sanctioned internationally, but, this was the first time Kim Jong Un has been personally sanctioned
Kerry said North Korea's actions present a very serious threat to international peace and security
Tensions have soared since Pyongyang carried out its fourth nuclear test in January, followed by a series of missile launches
Beijing is wary of pushing the North too far, fearing a regime collapse that could create a refugee crisis on its border
US Strategic Command said it detected and tracked three North Korean missile launches,just over a week after Pyongyang issued threats to respond to the planned deployment of a US anti-missile system in South Korea