A strong earthquake jolted the central North Island early on Saturday.

GeoNet said the 'severe' magnitude 5.9 quake happened about 5km southwest of Taumarunui at 4.51am.

The earthquake was 9km deep and the intensity was severe.

The quake was reportedly felt across much of the North Island, including Auckland, and as far as the top of the South Island.

By 6am, nearly 23,000 'felt reports' had been filed to GeoNet. At least 11 aftershocks, ranging between magnitudes 2.2 and 3.7, followed.

Fire and Emergency New Zealand said there were no quake-related callouts at all.

Aftershocks could go on for a week or longer - seismologist

A seismologist told RNZ the earthquake was the first recorded in that spot.

While Earth Sciences New Zealand duty seismologist Sam Taylor-Offord said it was a normal faulting earthquake, so not unexpected, and could have occurred on one of the few mapped faults in the area. It was the first to strike since records began in the early 1800s.

Taylor-Offord said larger earthquakes were not common in the wider area.

"The nearest earthquake in the country was in 1946, south of Te Kūiti, magnitude 5.4.

"But I would remind people who might have felt them, there was an earthquake in 2023 in Te Aroha, magnitude 5.1, which is very similar to this, smaller. There was also a deep earthquake in the region in October 2018, which was a 6.2, and that was felt down to Otago.

"So they do happen in the region. They're just much less frequent than other parts of the country."

Taylor-Offord said there had been more than 50 aftershocks, up to 3.7 in magnitude, within three hours.

"It could go on for a week, more or less, regularly... and then we expect things would taper off. But we could still be seeing earthquakes here in years to come that are associated with this one, just much, much smaller."

While nearly 23,000 'felt reports' had been filed to GeoNet, Taylor-Offord said it only recorded the first five minutes.

"So that 23,000 is the people that woke up and reported it, and I could not tell you how many more have been reporting it in the hours since, so it could be in the high tens of thousands."

Minor damage in Taumarunui

The mayor of the Ruapehu District confirmed there had been some minor damage in Taumarunui.

Weston Kirton told Saturday Morning one or two commercial buildings had been affected, "glass broken and the like".

There had also been minor slips on the roading network, including one blockage where someone could not get out.

Kirton, who lived just three kilometres south of the epicentre, described the earthquake as traumatic.

"My bedroom has got lights that were shaking, and I thought things were going to start falling over. We did have photos, and what have you, fall over, but it was one of those moments where you don't know whether it's going to get worse, but as it turned out, it was five or 10 seconds of, just, trauma, and then of course it quietened down.

"It certainly was traumatic. I've lived here all my life and it certainly was the largest I've experienced in my lifetime."

Minor slips reported

Manawatū-Whanganui Emergency Management Group urged motorists to take care while driving after minor slips were reported in the area.

"Emergency services and roading crews are assessing the situation, but a fuller view of any impacts is unlikely to be available until daylight," it said.

No injuries or other damage had been reported.

The Emergency Management Group expected aftershocks to continue throughout the morning.

"If people feel them, they should drop, cover, and hold. If you are in bed, the best thing to do is to stay there and cover your head and neck with a pillow."

'Strong and long' in the lower North Island

The earthquake felt like it would not end in Whanganui, according to a resident in the suburb of Springvale.

Cushela Robson described the tremor as a very strong, prolonged rolling motion.

"I thought, should I get out of bed? And if I did, could I stand? So I thought, no, probably, because I grew up in Wellington, I thought, no, I think it's probably better to stay in bed."

"Even when I did get up I had to be quite careful, because the movement was still quite strong."