Britain to help NZ rescue efforts after earthquake

New Zealand Prime Minister John Key has declared a national state of emergency as the death toll from Tuesday's earthquake in Christchurch rose to 75.

Police have said there is "incredible carnage right throughout the city", with "bodies littering the streets".

More than 300 people are still missing. Forty-eight were pulled out from collapsed buildings alive overnight.

British High Commissioner to New Zealand Vicki Treadell, who is in Christchurch, has told the BBC that the UK is sending firefighters to help with the rescue efforts.