International rescuers engaged in a wide-ranging search for earthquake survivors, just days after a strong 6.3 magnitude shock struck New Zealand's second largest city.

Rescuers from around the world have joined local teams of firefighters and residents. Japan has sent dozens of disaster relief team members.

Meanwhile, New Zealand has declared a national state of emergency.

On the scene technology such as thermal imaging cameras are being used to look for survivors.

The quake damaged and collapsed buildings, sending the death toll in the early days of the aftermath into the dozens. Among the damaged structures was a mall, businesses in the central district, wrecked buses, houses of worship, and local hotels. Many crushed cars were also seen.

Residents have asked for help for even basic necessities, such as portable toilets. Distraught friends and family of quake victims have also been part of the scene.