Primary and intermediate school students involved in a kapa haka competition in Blenheim were left shaken by the 6.6 magnitude quake.
The quake was centred 10km south-east of Seddon, in Marlborough, at a depth of 8km. It hit at 2.31pm and was followed by a series of significant aftershocks.
The Te Huinga Whetu regional school competition was being held at the Marlborough Boys' College Hall.
Students, teachers and supporters were evacuated, mid-way through one of the team's performances.
One of those evacuated, Nan Kahu, said it was scary for the children when Ruaumoko, the Maori demi-god of earthquakes, started rumbling. Event organisers decided to call off the competition.
Ngati Apa ki te Ra To Trust chief executive Paia Riwaka-Herbert said she was relieved all her staff got out of their central Blenheim office safely.
The office is in a villa, and staff watched as lights and the chimney shook from side to side. Ms Riwaka-Herbert said they didn't wait long to get out of the building.