At least 65 people have been killed in an earthquake that hit the New Zealand city of Christchurch.
Prime minister John Key said the death toll was expected to rise further after a 6.3 magnitude earthquake hit the city just before 1pm on Tuesday, collapsing buildings and sending bricks and other heavy debris toppling into busy city streets.
Video footage showed some multi-storey buildings collapsed in on themselves, and others with walls that had collapsed into the streets, strewn with bricks and shattered concrete. Footpaths and roads were cracked and split, and thousands of dazed residents wandered through the streets as sirens blared.
Groups of people helped victims clutching bleeding wounds, and others were carried to private vehicles in makeshift stretchers fashioned from rugs or bits of debris.
Christchurch mayor Bob Parker declared a state of emergency and ordered people to evacuate the city centre. Troops were deployed to help people get out and to throw up a security cordon around the stricken area, deputy prime minister Bill English said.
"It is a just a scene of utter devastation," Mr Key said after rushing to the city within hours of the quake. He said the death toll was 65, and may rise. "This may be New Zealand's darkest day," he told TV One News.
The spire of the stone Christchurch Cathedral toppled into a central city square and two buses were crushed by falling building debris. The airport was closed, and Christchurch Hospital was briefly evacuated before it was deemed safe and patients were returned.
Power and telephone lines have been knocked out, and pipes burst, flooding the streets with water. Some cars parked on the street were buried under rubble.
The multi-story Pyne Gould Guinness Building, housing more than 200 workers, collapsed and an unknown number of people are trapped inside. Television pictures showed rescuers, many of them office workers, dragging severely injured people from the rubble.
It was the second time a major quake hit the city of 350,000 in five months. The 6.3-magnitude quake struck closer to the city centre than a quake that heavily damaged Christchurch last September but caused no deaths when it struck before dawn on a weekend.