5.7 magnitude aftershock hits Culverden, felt in Christchurch

A strong 5.7 earthquake hit the South Island on Tuesday evening, toppling chimneys, closing a key road to Kaikoura and leaving spooked residents sleeping outside.

The 23km deep quake struck 20km southeast of Culverden at 6.13pm.

Damage, including toppled chimneys, has been reported in the North Canterbury town of Waikari.

Hillary Louis, a nearby resident who felt the quake, told Newshub it "was like an explosion going under the house".

"Now we are all congregated at one neighbour's house and we are all outside so we are sleeping outside tonight, we can't go back in the houses because they are so badly damaged."

Louis said her street was continually being struck by aftershocks.

"We are right in the zone, everyone is out of their houses, we've got lots of damage and they keep continuing every two minutes."

Canterbury Civil Defence said Inland Rd, the only route connecting Kaikoura to the rest of the region, had been closed because of the risk of further slips occurring after the quake.

The road would remain closed Wednesday morning, until engineers had assessed it. Assessments were expected to be completed by midday.

The closure meant a Defence Force convoy scheduled to ferry supplies into Kaikoura would not leave in the morning as planned.

Canterbury Civil Defence duty controller Brett Aldridge said people's safety was the top priority and staff would open the road as quickly as possible.

A Hurunui District Council spokeswoman said they hadn't received any calls from people requiring assistance.

Building inspectors would assess damage in Greta Valley and Scargill Valley today.

The quake was part of a cluster, starting at 6.10pm, ranging from magnitude 4 upwards.

More than 4000 people have reported feeling the quakes on the GeoNet website.

An NZME reporter in Christchurch said the first quake hit with a jolt and then continued rumbling for some time.

The quake was hardly felt by an NZME reporter in Kaikoura.