The bodies of at least 26 soldiers from the Second World War have been washed from their graves by rising sea levels in the Pacific.
The Japanese servicemen were buried on the Marshall Islands, which are only two metres above sea level at their height.
Climate change is already threatening their very existence and the grisly episode has highlighted the islands’ plight.
Tony de Brum, the Marshall Islands’ Foreign Minister, said: “There are coffins and dead people being washed away from graves. It's that serious.”
He was speaking at the UN climate change talks attended by 170 nations in Germany last week.
The skeletons were found on Santo Island after high tides battered the archipelago from February to April, he said, and more could be found.
Unexploded bombs and other military equipment have also washed up in recent months.
“We think they are Japanese soldiers,” Mr de Brum said.
“We had the exhumed skeletons sampled by the US Navy in Pearl Harbor (in Hawaii) and they helped identify where they are from, to assist in the repatriation efforts.”
Scientists believe global warming has raised average world sea levels as by about 19 cm over the past century as ice caps have melted, aggravating the impact of storm surges and tides.
A UN study released on Thursday found that changes in Pacific winds and currents meant sea levels in the region had risen faster than the world average since the 1990s.
Rising tides not only threaten to submerge island states but wash salt water onto the land, ruining vegetation and crops.
“We think they are (getting the message) but not quickly enough to climate-poof some of our more vulnerable communities,” Mr de Brum said.
Measures include raising homes on stilts, rebuilding roads and docks, and even abandoning some reefs.
The Marshall Islands were used as an administrative centre for the Japanese army during the Second World War before US forces invaded and occupied the islands.
As part of the Pacific Proving Grounds, the US carried out 67 nuclear weapons test there in the late 1940s and 1950s, contaminating the land and subjecting civilians to radioactive fallout that continues to affect health today.
Additional reporting by Reuters