North Korea on Friday said it "successfully" conducted a nuclear warhead explosion test, hours after an earthquake was detected near the country's nuclear site in the northeastern region, Yonhap News Agency reported. 
"The nuclear test finally examined and confirmed the structure and specific features of movement of nuclear warhead that has been standardized to be able to be mounted on strategic ballistic rockets," read an English statement issued by the North's nuclear weapons institute carried by the Korean Central News Agency (KCNA). 
It said that the standardization of a nuclear warhead will enable North Korea to produce as many "smaller, lighter and diversified" nuclear weapons as it wants. 
"This has definitely put on a higher level (North Korea's) technology of mounting nuclear warheads on ballistic rockets," the statement said. 
The North's nuclear provocation came after North Korean leader Kim Jong-un ordered his officials in March to conduct a nuclear warhead explosion test and more test-fires of ballistic missiles as soon as possible. 
South Korea's defense ministry on Friday said the yield of the blast is presumed to have been 10 kilotons, the largest ever conducted by Pyongyang. 

Source : QNA