Shaken Canterbury residents have spent a fitful night as 190 earthquakes rattled the region after yesterday's strong aftershock.
The 5.7 earthquake hit the South Island at 6.13pm, toppling chimneys, closing a key road to Kaikoura and forcing spooked residents to sleep outside.
The 23km deep quake struck 20km southeast of Culverden, near the epicentre of last week's massive Kaikoura quake.
Civil Defence is today warning people to stay away from Conway River as a slip on the Towy River formed a dam which is in danger of over topping.
The worst damage, including toppled chimneys, was reported in the North Canterbury town of Waikari.
Resident Kate McMillan said the rolling aftershock lasted for about 30 seconds.
"I grabbed the kids and ran outside. Everyone was out there."
McMillan went back outside during a couple of the stronger aftershocks in the night.
Her children, aged 8 and 11, found it "a bit of an adventure".
"They weren't too scared. It's just part of life at the moment."
McMillan didn't have any damage at her house and she wasn't aware of neighbours having damage.
Waikari School was opening at 10am.
Another resident, Hillary Louis, told Newshub the quake "was like an explosion going under the house".
"Now we are all congregated at one neighbour's house and we are all 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."
Other Canterbury residents rattled by yesterday's strong aftershock described it as "horrid" and "rolling for ages".
GeoNet said 190 earthquakes hammered the region in the past 12 hours. Five were over magnitude 4.
Canterbury Civil Defence said Inland Rd, the only route connecting Kaikoura to the rest of the region, was closed because of the risk of further slips after the quake.
The road would remain closed until engineers had assessed it this morning.
A Defence Force convoy scheduled to ferry supplies into Kaikoura would be delayed.
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 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.
Status of South Island roads
·State Highway 1 between Picton and Ward - OPEN but reduced to one lane in multiple places due to earthquake damage. Take extra care.
·State Highway 1 southern closure has been moved north of Cheviot to the Leaders Rd intersection at Parnassus. State Highway 1 between Parnassus and Ward - CLOSED due to earthquake damage. Controlled access for local residents and emergency services only between Parnassus and Goose Bay.
·State Highway 7 between Waipara to Springs Junction - OPEN (Lewis Pass) - down to one lane in places.
·State Highway 7A between Tekoa Range and Hanmer Springs - OPEN - no restrictions in place.
·State Highway 73 between Christchurch and the West Coast - OPEN - due to cracking some speed restrictions are in place over the highway.
Zone 1 - Flaxbourne Bridge damaged Zone 2 - Waima Bridge damaged
2 moderate slips Zone 3 - 6 major slips
9 moderate slips Zone 4 - Road open Zone 5 - Oaru Bridge damaged
2 major slips
5 moderate slips Zone 6 - Road closed to Cheviot Zone 7 - Wandle Bridge damaged
2 moderate slips