The government of <a href="https://en.wikipedia.org/wiki/North_Korea" id="mwAZQ" rel="mw:WikiLink" title="North Korea">North Korea</a> conducts its fifth and reportedly biggest <a href="https://en.wikipedia.org/wiki/September_2016_North_Korean_nuclear_test" id="mwAZU" rel="mw:WikiLink" title="September 2016 North Korean nuclear test">nuclear test</a>. World leaders condemn the act, with <a href="https://en.wikipedia.org/wiki/South_Korea" id="mwAZY" rel="mw:WikiLink" title="South Korea">South Korea</a> calling it "maniacal recklessness".