UPDATED: 5.44pm A strong earthquake's been felt in the lower North Island and Upper South Island.

The magnitude 5.5 quake was 34 kilometres deep and hit just after half past three.

It was centred 35 kilometers east of Seddon.

Almost 7000 people have reported feeling the earthquake, according to Geonet, with reports coming from as far away as Christchurch and the central North Island. 

Civil Defence tweeted that it was “a sharp shake”, and added a reminder to ‘drop, cover and hold’ in an earthquake situation.

Resident Murray Jones said it gave him a good fright.

"I just saw some of the things in the shed rattling and just stopped. I'm on the banks of the Awatere river so even though I feel them a lot, and they scare the hell out of me, they're probably not as bad as they are up in the township of Seddon."

Owner of SuperValue in Seddon, Kevin Kamat said the shaking lasted a few seconds.

"It was definitely a strong shake.

"Nothing fell off the shelves apart from a bag of chips but I think that was the wind" he said.

Kamat said there were about six customers in the store who all froze until the quake stopped.

Newstalk ZB caller Val is in Tawa in Wellington and told Andrew Dickens it was a pretty big jolt.

"I shot out of my chair as though someone had shot me. It was a nasty one yeah."

Maria is in Blenheim and said it also shook her about a bit.

"I was putting lipstick on but instead of on my lips, it ended up on my cheek. That's how bad the shake was."

Michael Duncan was upstairs in his 1924-built house in Wanganui East and watching the cricket when the jolt hit.

"The rubble started and I thought it was just a bus going by but then I heard creaks in the house and thought, 'Oh my goodness, this is another quake'. It went for some time," he said.

A few aftershocks have hit the Seddon region since the quake struck at 3.34pm, including a 3.8 magnitude  and a 3.3 magnitude, according to Geonet.

A strong 4.7 aftershock also hit at 4pm, Geonet said.

NZTA said there's no damage to State Highway 1 and no issues reported from the crews.

The road has remained open and will remain open until its planned 8pm closure.

The fire service has also not received any callouts following the earthquake.

St John spokesman Ian Henderson said the clinical control centre in Christchurch has also not received any calls.

"We have had no reports of injuries or damage," he said.

"This entire part of the country is still an active earthquake zone so we encourage people to stay in touch with friends and relatives especially those who you know are alone, frail or ill.

"It is also a good time to check your emergency kit, supplies, and emergency medications (if required) and have them all up to date."

More useful information can be found at http://getthru.govt.nz/