New Zealand authorities on Thursday said no-go zones in quake-hit Christchurch will be lifted and enlisted rugby stars to promote mental health services to help stressed residents.

Exclusion zones enforced by police and the military since last weekend's 7.0-magnitude tremor would be removed at 5:00 am Friday (1700 Thursday GMT), Christchurch mayor Bob Parker said.

Parker said the city centre should be safe to enter, provided there were no major aftershocks.

The removal of the barriers comes as normality slowly returns in the South Island city, where the focus is turning to the mental toll wrought on residents subjected to around 300 aftershocks since the main quake on Saturday.

Health Minister Tony Ryall said local All Blacks players Richie McCaw, Brad Thorn, Kieran Read and Corey Flynn would contribute to a campaign urging people in the disaster zone to seek help.

"Many people will need reassurance and practical advice as to what to do and where to go to get help," Ryall said.

The civil defence ministry said doctors were reporting a rise in the number of people presenting with stress and anxiety issues.

It said public health officials were working on "psycho-social support" for locals.

Rachel Hood said she decided to send her daughters Izra and Jasmine, who are three and one-years-old respectively, to stay with their grandmother in Wellington after a shallow 5.0 tremor hit on Wednesday morning, sending frightened residents fleeing into the streets.

"I just don't want traumatised children for the rest of their lives so I'm sending them away before it get worse," she told the Dominion Post newspaper.

Police this week reported a 53 percent rise in domestic violence since Saturday's quake, attributing it to "the stressful situation people are currently in".

Meanwhile, supermarket operator Foodstuffs announced the first job losses from the quake, saying its store in suburban Kaiapoi was irreparably damaged and 86 workers were being made redundant.

"We are very distressed that the damage to the supermarket has meant we are unable to re-open and we are doing everything we can to help all of those affected," Foodstuffs chief executive Steve Anderson said.

Christchurch remains in a state of emergency after the earthquake, which caused damage estimated at four billion dollars (2.7 billion US).

However, some aspects of life were returning to normal, with officials lifting advice for residents to boil drinking water to avoid the danger of contamination.

Bus services also resumed and education authorities said some schools would be allowed to reopen after their buildings were deemed safe.