North Korea claims to have tested faster, less detectable missiles that can target all of South Korea

If confirmed these trials could mark yet another military milestone in a busy year for the secretive state

North Korea claims to have carried out rocket tests that would significantly increase its military attack capability.

The trials are particularly significant as the missiles apparently used solid - rather than liquid - fuel, meaning they could essentially be stored pre-fuelled, dramatically decreasing their launch time.

Removing the need to fuel missiles makes it much more difficult to detect the signs of launch preparation as the weapons are more mobile and quicker to prepare. 

North Korea’s state media said leader Kim Jong Un expressed delight after observing the successful testing of a "large-output solid fuel rocket engine" which made an "earth-shaking" sound as it spat out a large beam of fire. 

Mr Kim said the test would enhance a missile capability which could "mercilessly" strike enemies, an apparent reference to South Korea and the United States. 

The launch has not yet been independently confirmed, with South Korea’s Defence Ministry saying it will need to be analysed. 

It would seem the tests are intended to use solid propellants to fuel missiles with a range of 400-500 kilometers – which would put the entirety of South Korea within striking range.

It is thought North Korea’s increased weapon testing is a response to the on-going annual military drills staged by South Korea and the US . 

The drills - the biggest yet - follow North Korea’s fifth nuclear tests and a long-range rocket launch, both of which took place earlier this year. 

North Korea has also announced plans for a nuclear warhead able to leave the Earth’s atmosphere and re-enter to hit a specified target.

If achieved, such a development would enable the country to develop weapons able to reach mainland USA.

On Thursday South Korea’s President, Park Geun-hye, raised security after North Korea allegedly threatened to attack her presidential palace.