North Korea's latest nuclear test yield estimated at 250 kilotons: US monitor SEOUL (AFP) - North Korea's latest nuclear test probably had a yield of 250 kilotons, a US monitoring group said on Wednesday (Sept 13) - much higher than official estimates. Pyongyang conducted its sixth and largest nuclear test on Sept 3, saying it was a hydrogen bomb that could be fitted into a missile. That prompted global condemnation and heightening tensions over its weapons ambitions. The US Geological Service put the magnitude of the resulting earthquake at 6.3, and the Comprehensive Nuclear Test Ban Treaty Organisation and Norwegian...