Hours after announcing its third successful nuclear test, North Korea threatens escalation.<br/> <br />A Foreign Ministry statement broadcast on state TV said further U.S. hostility would complicate the situation and lead to stronger responses from the North.<br/> <br />Tuesday's test has prompted angry reactions from the region and calls for harsher international penalties on the already heavily-sanctioned country.<br/> <br />An Austria-based nuclear test monitoring agency confirmed seismic activity of magnitude 4.9.<br/> <br />The executive secretary of the Comprehensive Nuclear Test Ban Treaty Organisation said the location of the latest blast was consistent with North Korea's 2006 and 2009 tests.<br/> <br />(SOUNDBITE) (English) EXECUTIVE SECRETARY OF THE COMPREHENSIVE NUCLEAR TEST BAN TREATY ORGANISATION (CTBTO), TIBOR TOTH, SAYING:<br/> <br />"This DPRK announced nuclear explosion is going in the wrong direction, this is a wrong step in the wrong direction and this is a challenge to this norm observed by the international community of not carrying out nuclear weapon explosions."<br/> <br />The agency says the seismic activity indicates Tuesday's test was twice as big as the 2009 blast but that it will take days for it to be officially verified.
