The shaking was centered near Lyteltton Harbor and was felt in the cities of Canterbury and Christchurch, which had been jarred by a major 6.3 quake in February that killed 181 people.
Social media included reports from people who experienced a sizable shaking, however, emergency agencies in Christchurch told Radio New Zealand they did not receive any calls for help.
TVNZ said the quake was felt strongly in the stands at the city's Hagley Park rugby stadium where New Zealand's All Blacks was taking on Argentina.
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