New Zealand PM says Christchurch quake death toll may rise

The New Zealand government says at least 65 people have been killed in an earthquake in the city of Christchurch.

Many more are still trapped in damaged buildings - one report says as many as 200.

Passengers on two buses were crushed by falling debris. The quake, with a magnitude of 6.3, happened in the middle of the day and caused widespread panic.

Speaking on TVNZ the country's Prime Minister John Key says the toll was expected to rise further, adding: "We may be witnessing New Zealand's darkest day."