Quake-fatigued Christchurch escaped the worst of the effects of this morning's sequence of frightening, deadly earthquakes.

But the city's residents remain scarred from the killer 2011 quake, which took 185 lives and devastated the city.

Christchurch Civil Defence and Emergency Management activated its Emergency Operations Centre and residents within a kilometre of the Canterbury coast were told to evacuate to higher ground.

Tsunami sirens sounded and schools were opened as evacuation centres. The tsunami warning has been withdrawn, but people are being told to remain out of the water and off beaches and shore areas.


Evacuated residents reported a long night.

They shared tales of police patrolling streets, ordering residents out of homes, and gridlock as people fled to higher ground.

Kaiapoi woman Kineta Booker said the quake was "long and scary".

"And then when it shifted into second gear ... can't believe we've got to get used to these all again."

Many evacuees hunkered down in their vehicles at the Pak n'Save car park in Rangiora.

Booker spent much of the night in her car with her husband and toddler. Supermarket staff were checking on people in the car park.

Later the couple headed north towards Oxford but stopped at Cust, about 35 minutes north of Christchurch.

"Hundreds upon hundreds of people are parked up, sleeping on the side of the road. It's surreal."

Trev tweeted his thoughts.

"Wow. Felt that quake in Chch big time."

The return home was not a happy one for everyone.

Melissa Mill, her husband and daughters returned to their New Brighton home to discover it had been looted.

Along with a work truck, electronic equipment and equipment for their disabled daughter was taken.

"It's really horrid. We took our family away to be safe and came back to all of this."

Two rest homes were also affected by the evacuation order and the port advised large moored vessels were safer out at sea.

However, the airport was open as usual.

The quakes have damaged roads, with cracks and slumps reported in rural North Canterbury.

Major highways have been closed, including State Highway 1 between Picton and Waipara, and State Highway 7 between Waipara and Springs Junction. The Lyttelton Tunnel is open.

New Zealand Cricket (NZC) is monitoring the situation in Christchurch, with the Blacks Caps' first test against Pakistan due to start in the city on Thursday.

Christchurch is also due to host NZC's annual general meeting on Wednesday.

Residents in the garden city appear to have escaped injury, but those further north were less fortunate.

St John was sending helicopters to North Canterbury as calls for help flooded in. Spokesman Ian Henderson said they had reports of injuries from the earthquake-affected area, including Culverden and Kaikoura.

Two people have died; one in Kaikoura and another in Mt Lyford.