A strong undersea earthquake measuring 6.6 on the Richter Scale hit off the northeast coast of New Zealand today. The Pacific Tsunami Warning Centre issued a local tsunami warning but said there was no threat of a widespread destructive tsunami. According to US Geological Survey, the quake struck at 1:03 am (local time) around 550 kilometres east of Auckland, and had its epicenter 90 kilometres below the surface. There are no immediate reports of any damage or casualties.