The major earthquake that struck central New Zealand on Sunday afternoon has caused damage to buildings and disrupted transport in the Wellington region.

Photo: SUPPLIED

The first shake, which Geonet says measured magnitude 6.5, struck at 5.09pm at 20km east of Seddon at a depth of 17km.

A second quake, registering 5.5, hit minutes later at 5.13pm at a depth of 5km, 50km east of Seddon.

The major quakes are the latest in a swarm of shakes that have been hitting the centre of the country since Friday.

On Sunday there had been 22 aftershocks of magnitude 4 or above by 10pm.

Police have closed some roads in central Wellington including parts of Willis Street, Wakefield Street and Bolton Street due to the risk from damaged buildings.

The Mercure Hotel on Willis Street has been evacuated after structural damage was discovered following the quake.

Wellington region civil defence controller Bruce Pepperell says one floor of the hotel has slumped and all of the guests and staff have been evacuated.

There also reports of road damage and minor building damage at Featherston Street which has been closed from Waring Taylor Street to Johnson Street.

Part of a concrete facade of a building in Featherston Street is reported to have fallen.

Cracks have appeared in the Readings Cinema carpark, dropping debris which has caused damage to Wakefield Street.

Photo: RNZ

Mr Pepperell says there hasn't been much water damage but a water main broke in a building near Parliament, a number of ceilings collapsed and cladding has come away from the sides of buildings.

He says there is also broken glass and a walkway has come away from a building at Wellington City Council and the regional council building has a split.

Mr Pepperell says power was cut in the suburb of Karori for a time but electricity has now been restored.

There are now less than 24 homes in Wainuiomata without power overnight on Sunday, earlier 446 homes and businesses there had their power cut.

Inspector Marty Parker in Wellington is asking people to avoid driving if possible on Sunday night, as road conditions are not yet known, but it is clear there is glass on roadways in some areas.

The Fire Service says they've been notified about cracks in stairwells, broken windows and falling tiles, but there have been no reports of fires.

Fire trucks were deployed across Wellington to respond to fire alarms triggered by the earthquake.

Only minor damage has been reported in Porirua and the Hutt Valley.

One injury reported

Wellington Free Ambulance says a man has been taken to hospital after being knocked out by a falling television set.

The ambulance service says the man, who is in his 40s, received minor injuries.

It says ambulances have been responding to several calls relating to anxiety and chest pains.

Personal accounts

A family from Nelson in Wellington on holiday say they were terrified after a wall in their apartment collapsed.

Carol Cooper, her husband and two children were in their Quest serviced apartment on Lambton Quay when an internal wall suddenly fell down.

Mrs Cooper says she was on the seventh floor of the building when it began to shake violently and she grabbed her children and stood in the doorway.

She says she didn't know whether the building would remain standing due to the force of the quake.

"The kids by that stage were absolutely screaming hysterically and panicked when the inside wall started coming away, yeah I wasn't sure how much more the building was going to take."

Kay Baxter was in the aisle of a supermarket in Newtown, and says tinned goods started falling off the shelves into the aisles.

She says a notice came over during the quake asking customers to evacuate the building and people eventually left once the shaking stopped, leaving their shopping and trolleys.

Ms Baxter says the aisles were covered in cans and smashed bottles of tomato sauce, but the supermarket wasn't busy so it was easy to evacuate and outwardly most people remained calm.

Julie Collier from Masterton was pruning her roses when the quake struck.

"We have an old two storey historic homestead and every window was rattling and the whole house was shaking."

Transport in Wellington

All trains from Otaki in the north to Blenheim in the south, including the capital have been suspended until further notice.

Kiwirail says it is carrying out track inspections, but if the aftershocks continue all commuter and freight trains may be suspended for some time.

All TranzMetro rail lines have been closed until further notice while checks are done on bridges, tunnels and other structures.

No replacement buses are available and Metlink is warning Wellington commuters to expect delays to normal bus services.

Wellington airport says flights in and out of the capital have resumed on Sunday evening and the runway has not been damaged.

The runway was closed for inspection immediately after the main quake.

Damage at King's wharf

Wellington's harbourmaster says the quake has caused major damage at King's wharf.

Captain Mike Pryce says the damage is at the south end of Kings wharf, where the Bluebridge ferry Santa Regina and Strait Shipping berth.

He says about 15 metres of land has slumped into the harbour and there are massive cracks the whole way around.

Captain Pryce says the road is not a public road, and access has been restricted.

Mobile phone services working again

Telecom says most of its service are now back to normal after some people were unable to text or phone following the quake.

Spokesperson Lucy Fullerton says there are still isolated power cuts that may effect some people's broadband services, however there are no longer problems for anyone trying to phone or text.

Vodafone says all 15 transmission sites in Marlborough and Wellington that went down after the quake struck are now up and running.

Aftershocks likely to continue for a week - GNS Science

GNS Science says there is a 30% chance of a magnitude 6 aftershock and there are likely to be nine quakes of up to magnitude 5 in the next week.

It says the aftershocks are likely to continue for longer than a week.

A similar series of quakes of a lower magnitude near Seddon in 2005 lasted for 11 days.