Australian Prime Minister Julia Gillard has extended the nation's condolences to the families of the Pike River miners.
Ms Gillard said 29 families had been hoping, praying, and waiting to hear good news and now they had heard the most terrible news.
Among the dead were two Australians.
New South Wales Premier Kristina Keneally called on all government agencies in the state to fly the Australian flag at half mast on Thursday as a mark of respect.
She also asked that the Australian and New Zealand flags on Anzac bridge in Sydney be flown at half mast and the same be observed on the harbour bridge.