Strategypage discusses the issue.
Combined with continuing North Korean ballistic missile tests, I really believe we can confidently say that Iran is hiding their nuclear programs in plain sight in fellow Axis of Evil member North Korea.
Have a super sparkly day.
UPDATE: Call it 20 to 30 kilotons.
UPDATE: More detailed news. This may be North Korea's fifth nuclear test and second this year, but it did inspire "broad condemnation" of North Korea. So we've got that going for us, eh?
UPDATE: Oddly, Iran is not mentioned:
North Korea is touting technological progress in its nuclear program, saying after a nuclear test Friday that it can now produce “smaller, lighter and diversified nuclear warheads of higher strike power.” But it is also making strides in its missile program, analysts say — advances that could enable it to outsmart missile defense systems, which could make the missiles more attractive to potential customers.
Egypt is mentioned, despite its peace treaty with Israel--but not Iran.