The northern part of New Zealand has been shaken by a strong earthquake this morning.

The 5.1 magnitude quake hit at a depth of 7km about 5km south of Te Aroha in the Waikato region at 5.39am.

More than 20,000 people reported feeling a shake in the areas nearby, including Hamilton, Tauranga, Auckland, and Rotorua.

It was followed by two 2.7 magnitude earthquakes in the same spot at 5.47am and 5.51am.

About 8000 people reported feeling the first aftershock, and about 4000 reported feeling the second.

Truck driver Darryn Phayer said his 25-tonne truck swayed sharply in the first earthquake.

"The truck started violently shaking and I thought 'oh what's going on here', but literally, prior to that, in the farm across the road from the yard, a bunch of dogs started barking and I thought 'oh what's upset them' and within a couple of minutes, it was up on GeoNet.

"[It] scared the living daylights out of me, to be honest."

On the east coast, Pauanui resident Christine Harrison said it was the strongest quake she had ever felt.

"It was a strong jolt in that it made me grab the edge of the bed to really hold on but as quickly as it started, it stopped."

It comes after a 3.9 magnitude quake hit in the same spot last week.

GeoNet said they were likely on the same fault system.

The area last had a strong quake in 1972 with a 4.9 magnitude earthquake, GeoNet said.

A 1972 bulletin, published by the New Zealand Society for Earthquake Engineering, reports a 5.1 magnitude quake in the area, with damage confined to the region but also felt as far as Mangakino and Whakatāne.

There was also said to be numerous aftershocks the next month.