All 29 miners trapped in a New Zealand coal pit since Friday are believed to be dead after a second explosion.
Police Supt Gary Knowles said there was no hope that anyone could have survived the “massive” underground blast at the Pike River mine on South Island.
Prime Minister John Key said the loss of life was a national tragedy.
There had been no contact with the men – 24 New Zealanders, two Australians, two Britons and a South African – since the first explosion on Friday.
The Britons were Peter Rodger, 40, and Malcolm Campbell, 25, who were both originally from Scotland.
“Many British citizens have made their home in New Zealand and the loss of Mr Rodger, Mr Campbell and their colleagues will have touched the hearts of many in the UK,” said UK Foreign Secretary William Hague.
Supt Knowles, who was leading the rescue operation, said there had been another explosion at 1437 local time (0137 GMT) inside the mine.
“It is our belief that no-one has survived and everyone will have perished,” he told reporters.
“I was at the mine myself when this actually occurred and the blast was horrific, just as severe as the first blast and we’re currently now moving into recovery phase.
“This is one of the most tragic things I have had to do as a police officer.”
Rescuers had been preparing to go into the mine on Wednesday, but information suggested the levels of methane gas were too high.
Shortly afterwards, the second explosion happened. It was larger and stronger than Friday’s blast, and lasted about 30 seconds, officials said.
The chief executive of Pike River Coal, Peter Whittall, said it would make every effort to retrieve the bodies of the men, aged between 17 and 62.
“We want our boys back and we want to get them out,” he told reporters.
Mr Whittall said the families were ”absolutely devastated by the news”.
”They had all held out hope that their son, their brother would be the lucky one,” he said, before adding with tears welling up in his eyes: “I’m unlikely to see my workmates again”.
Family members wept, shouted and fell to the floor after hearing the news, Grey District mayor Tony Kokshoorn said.
“People shouted out in anger, they are sickened by the whole thing. A lot of them felt misled,” he added. “It’s unbelievable. This is the West Coast’s darkest hour. It doesn’t get worse than this.”
Lawrie Drew, the father of 21-year-old miner Zen Drew, later told reporters: “I am still hoping that somebody can be found that is still alive.”
The prime minister said he would travel to the area on Thursday to meet the miners’ families and thank the resue crews.
“New Zealand is a small country, a country where we are our brother’s keeper, so to lose this many brothers at once strikes an agonising blow,” Mr Key told a news conference in Wellington.
“The 29 men whose names and faces we have all come to know, will never walk amongst us again. We are a nation in mourning.”
He also offered his condolences to Australia, South Africa and the UK.
Mr Key praised all those involved in the rescue attempt, and said there would now be a full inqNew Zealand Prime Minister John Key: ”We are a nation in mourning”
uiry into how the tragedy had happened, with the aim of making sure it was not repeated.
Governor-General Sir Anand Satyanand said the disaster would be felt at many levels, and was a great personal loss for the individual families and friends of those who died.
“There will be few on the West Coast who do not have a shared connection of some kind with those on whom this tragedy has impacted most directly,” he said.
It was not immediately clear what triggered the second blast. However, Mr Whittall said it was not thought that any rescue work caused it.
“To the best of my knowledge, absolutely nothing that was being done up there has caused this,” he added. “This has come from somewhere up in the mine. We weren’t doing anything in the mine other than in the fresh air and that wouldn’t have caused any explosion.”
Air samples taken from inside the mine through a 162m (530ft) bore-hole completed on Wednesday had shown dangerous levels of methane and carbon monoxide, preventing rescuers from entering the mine.
Two robots had been sent into tunnels of the mine and a third was on its way in the hope of gaining a clearer picture of the conditions underground.
Relatives of some of the miners had earlier questioned why rescuers had not immediately entered the mine after the first blast.
But Mr Whittall defended the decision to keep rescue workers out of the mine. “It’s dangerous and it’s hazardous and the rescue teams would be putting their lives gravely at risk,” he said.
“While we were there and making that assessment, exactly what we said could happen, happened.”
Mining expert David Feickert told TVNZ it was likely the men became unconscious from carbon monoxide prior to the second explosion and so would not have felt the blast.
Pike River is not far from the Strongman Mine, where an underground explosion killed 19 men in January 1967.
New Zealand’s worst mining disaster was in 1896, when a gas explosion at the Brunner mine, also near Greymouth, left 65 miners dead. It accessed the same coal seam as the Pike River mine.