Fifty per cent of Christchurch now has a basic mains water supply following Tuesday's earthquake but people should still conserve water.

Rescuers are still looking for survivors in the rubble from Tuesday's 6.3 magnitude earthquake in Christchurch, but the chance of more live rescues is becoming "unlikely", Civil Defence Minister John Carter says.

Television bosses were in complex talks with advertisers yesterday to bring commercials back into their news schedules.

In the minutes after Tuesday's earthquake, the people of Santa Maria Ave, Redcliffs, gathered at the top of the street and hugged and cried.

Emergency teams hoping to find survivors in the rubble have switched focus to the grim task of retrieving the dead.

Rock near the quake's epicentre may have compounded the effect of the tremor by reflecting greater seismic activity towards Christchurch city.

"I have lost a leg. They had to cut it off to save me." Those were the first words rescued student Kento Okuda said to his mother.

A woman found beneath the rubble of a building held her dead brother's hand as she cried out for help from under the debris - and her heart-wrenching cries prompted rescuers to carry on digging until they freed him.

Baxtor Gowland was born two weeks after the September earthquake in Christchurch. Yesterday, he was named the youngest victim of Tuesday's quake.

As many as 22 tourists are thought to be buried in the rubble of Christ Church Cathedral and its spire.

The people left in Bexley grabbed spades and started again, shovelling and scraping at the charcoal grey sludge which clung to their homes.