New Zealand issues tsunami warning after powerful quake

New Zealand issued a tsunami warning for southern coastal areas today, following a powerful 7.4 earthquake near the South Island city of Christchurch around midnight.
"A tsunami is possible," the national civil defence organisation, which is in charge of New Zealand's emergency management, said in a bulletin.
"The first wave activity may not be the most significant," it said, adding tsumanmi activity would continue for several hours.