Strong aftershocks have rocked New Zealand following a 7.8-magnitude earthquake that killed two people. The South Island has seen hundreds of tremors, including a 6.3-magnitude quake, after the initial one struck after midnight on Monday. The epicentre is northeast of Christchurch, near the town of Kaikoura which has been cut off by landslides. There are believed to be up to 1,000 tourists strande