North Korea threatened today to launch a “sacred war” against South Korea even as a delegation from Seoul travelled across the countries’ heavily fortified border for a meeting on a stalled joint tourism project.

The gunman in the US university massacre had troubled his parents as a child because he would not speak, news reports in South Korea said today.

A North Korean diplomat admitted the country’s nuclear test was smaller than expected, and claimed the country was still to detonate a larger device, a South Korean newspaper reported today.