north korea missile tests 2016
North Korean leader Kim Jong Un meets scientists and technicians in the field of researches into nuclear weapons in this undated photo released by North Korea's Korean Central News Agency (KCNA) REUTERS/KCNA

North Korea has reportedly fired two ballistic missiles 300 miles (500 km) into the Sea of Japan just hours after claiming it had managed to miniaturise nuclear warheads and days after threatening to carry out nuclear strikes against the US. According to South Korean news agency Yonhap, the two missiles were launched from the city of Wonsan, from where other tests have been carried out.

North Korea conducted other missile tests on 3 March in retaliation for tough new economic sanctions imposed by the UN Security Council. The sanctions were imposed after the fanatical Communist regime conducted nuclear tests in January 2016. The sanctions include the blacklisting of people and organisations linked to the government. All cargo entering and leaving the North will also now be inspected amid concerns North Korea could try and export nuclear technology to terror groups.

outh Korean protesters burn an effigy of North Korea leader Kim Jong-Un during an anti-North Korea rally in Seoul, South Kore Chung Sung-Jun/ Getty Images

North Korea has already threatened to conduct pre-emptive nuclear strikes in response to joint military exercises being conducted by the US and South Korea, the biggest ever seen in the region and described as "nuclear war moves" by the North.

On 8 March, the country's ruling party newspaper Rodong Sinmun published a photograph said to show leader Kim Jong-Un beside a nuclear warhead which was small enough to fit on a ballistic missile. Some experts have cast doubt on the claims, but the possibility has ratcheted up tensions even further, coming only days after the North said it would turn Washington and Seoul to "flames and ashes."

North and South Korea are officially still at war and the DMZ between the two countries is the most militarised in the world - and one of the tensest borders on earth. South Korea's Joint Chief of Staff (JCS) told Yonhap: "The military is keeping close tabs on the situation and prepared to deal with any North Korean provocations."