The families of the many missing Japanese students feared killed in the collapse of the CTV building have told of their anguish.

Hundreds of people displaced by Tuesday's earthquake have set up camp at Christchurch welfare centres and more are flooding in.

A 52-year-old man is in a stable condition after having both legs amputated by a visiting surgeon at the PGC building.

Smashing his way into his devastated home today, Christchurch man Ed Langston appeared somewhat resigned to having lost his house and business in Tuesday's deadly earthquake.

Police have delayed releasing the names of those confirmed dead and for whom there are serious concerns.

Credit rating companies say there is no immediate need to change the credit ratings of insurers because of the Christchurch earthquake but Moody's Investors Service said ratings pressure may develop over time on the banking sector.

There is no possibility of survivors in the rubble of the Christchurch Cathedral, police said this afternoon.

Police and security staff are worrying about the possible further collapse of building facades.

Personnel at the PGC building in Christchurch have switched their focus from trying to find survivors to recovering the dead, the company says.

Rescuers have found no survivors at two Christchurch CBD buildings where signs of life were reported this morning, the Fire Service says.

The family of a woman feared dead in the earthquake has suffered another cruel blow with her home being burgled while her children waited for news.