A tsunami warning was issued following the 8.1 quake, at around 8:30am. People located between the Bay of Islands and Whangarei, between Matata and Tolaga Bay, including Whakatane and Opotiki, and on Great Barrier Island have been told to immediately move to higher ground. "Walk, run or cycle if at all possible to reduce the chances of getting stuck in traffic congestion," the National Emergency Management Agency said on Friday. "The earthquake may not have been felt in some of these areas, but evacuation should be immediate as a damaging tsunami is possible. "Do not stay at home". Officials warned that tsunami activity could continue for several hours and the "first wave may not be the largest".