Terrified residents were fleeing Seddon last night after a 5.5 earthquake rattled the quake-weary town.
The aftershock that struck just before 9 o'clock last night was more than some residents could take, with at least one family leaving town for good.
Red Cross team leader Ben McKinnon said the succession of strong aftershocks was proving too much for some locals.
"We've actually just had people turn up after this latest aftershock who were heading for Nelson tonight.
"They've decided they don't want to live in Seddon any more. They've got very young kids and they're going nuts so they just threw everything into the car and took off.
"There's a lot of very anxious people and anxious kids as well," said McKinnon, who was manning a welfare centre at Seddon School.
Despite widespread damage to homes at the epicentre of Friday's quake there have been just five injuries, including one person with a broken back.
But there were many lucky escapes, including a Seddon farmer and his pregnant wife who hid behind a quad bike as an avalanche of boulders landed around them.
Sam and Sarah Kersten, with 18-month-old Eliza, hid behind the bike after going out to check on livestock on their farm.
Farm owner Locky Taylor watched in horror, knowing the family were out tending pregnant ewes. "It was something like an air raid. We were ... watching the trees fall and the boulders coming down."
Pregnant Sarah, a well-known local singer, was rushed to hospital with suspected appendicitis yesterday.
Last night's quake struck at a depth of 18km about 25km south-west of Seddon and was the third biggest since Friday's 6.6 quake, and made sure emotions would run high into a third day.
One family remained at the centre last night after their quake-damaged home was the last property in town to be hastily patched up.
Said council recovery manager Dean Heiford: "Five people were staying overnight at the welfare centre in Seddon School but this shake might push more people out there."
GNS scientists warned of a 20 per cent risk of another 6+ Richter scale quake in the next seven days.