Experts have said it could take weeks or months before the bodies of the victims of New Zealand's mining disaster were recovered.
Pike River Coal chief executive Peter Whittall said the company was determined to recover the remains of 29 men, including two Britons, who were declared dead after two explosions deep underground.
But there are still very high levels of potentially explosive gases in the mine and Mr Whittall said various options were being considered to make the mine safe but it could take weeks. Prime minister John Key said it was possible the operation could take months.
Pete Rodger, 40, from Perthshire, and Malcolm Campbell, 25, from St Andrews, Fife, were among the missing miners.
Recovery teams were prevented from entering the mine by high levels of potentially explosive methane and other toxic gases blamed for two huge blasts inside the Pike River Coal mine.
The first explosion last Friday left the 29 men missing up to one and a half miles underground and officials insisted there was hope for them. But after Wednesday's second blast, police and mine chiefs said no-one could have survived.
The tragedy deeply shocked the country and devastated families who - buoyed by the survival tale of Chile's 33 buried miners - had clung to hope that their relatives could emerge alive.
Mr Whittall said mine operators were determined to bring out the men's bodies, but testing showed gas levels surged again soon after Wednesday's explosion and that another explosion was possible.
Mr Key again met relatives of the victims and promised them a thorough investigation. "They have accepted that their loved ones are gone - but they want answers," he said.
Flags flew at half-mast across New Zealand and special church services were held for people wanting to show respect for the miners. In parliament, MPs wearing black passed a condolence motion.