South Korean intelligence reports suggest North Korea is preparing to test-launch an intermediate-range missile at a time of escalating military tensions on the Korean peninsula.
WHAT ARE THE SIGNS A TEST COULD BE IMMINENT?
The South Korean Defence Ministry has confirmed intelligence reports that North Korea has transported at least one mid-range missile by rail to its east coast, and mounted it on a mobile launcher.
South Korean media reports that two missiles have been prepared.
WHAT KIND OF MISSILE IS IT?
The Defence Ministry has declined to identify the specific missile type, saying only that it appears to be an intermediate missile with "considerable range".
Media reports have cited senior military and government officials who identified the missile(s) as a mid-range "Musudan".
WHAT DO WE KNOW ABOUT THE MUSUDAN?
Not a great deal. The Musudan was first unveiled as an indigenous missile at a military parade in Pyongyang in October 2010, but has never been tested.
Analysis by security consultants IHS Jane's suggests the Musudan is an intermediate-range, road-mobile, liquid-propellant, single warhead missile based on the Russian R-27 and using adapted Soviet Scud technology.
Mounted on a wheeled transport-erector-launcher vehicle, it could be launched within 15 minutes of the launcher being positioned.
WHAT IS THE ESTIMATED RANGE AND PAYLOAD?
IHS Jane's puts the estimated range at anywhere between 2,500 and 4,000 kilometres (1,550 to 2,500 miles). The lower range covers the whole of South Korea and Japan, while the upper range would include US military bases on the Pacific island of Guam.
The potential payload size has been put at 1.0-1.25 tonnes.
IS IT NUCLEAR CAPABLE?
Theoretically yes, but most experts believe North Korea has yet to master the miniaturisation technology required to fit a nuclear warhead onto any of its missiles.
ARE THERE ANY DISSENTING VOICES?
Yes, German missile experts Markus Schiller and Robert Schmucker who have conducted extensive research into North Korea Korea's missile program, believe the Musudan is a "phantom missile".
The mock-up displayed in 2010 was "poorly manufactured" which suggests the North was far from a working prototype, Schmucker says.
"The Musudan, as such, does not exist," Schmucker says. "The North may well conduct a missile launch, but it will not be a Musudan. If it launches a mid-range missile, it will almost certainly be one it procured from overseas."