LONDON, England (CNN) -- Rescuers have recovered eight bodies from a helicopter crash Wednesday in the North Sea about 13 miles off the northeastern coast of Scotland, officials said.
The search continues for another eight people who were aboard the helicopter, Hayley Kelly, the press spokeswoman for Grampian police, told CNN.
The helicopter was returning from the Miller Platform, a drilling operation in the North Sea, said Brian Taylor, who represents the drilling contractor.
Ten members of the drill crew were on the Bond AS 33L Mk2 helicopter -- nine from the United Kingdom and one from elsewhere in Europe, he said, without going into further details. He did not identify the other six people on board.
Two life rafts spotted in the water were overturned, the Maritime & Coastguard Agency said.
The bodies were found in the water, not in the helicopter, said Suzanne Todd of the agency. All were wearing survival suits.
Two Royal Air Force helicopters and a marine patrol aircraft were sent to the area, the agency said. The volunteer Royal National Lifeboat Institution boats also responded.
Eleven vessels, including private ships, are aiding in the search, the Maritime & Coastguard Agency said.
"Conditions for search have been excellent -- very light winds, good visibility, slight sea," Todd said.
It is the second crash of a helicopter in the North Sea in less than two months.
A Super Puma helicopter ditched about 120 miles east of Aberdeen while approaching an offshore platform on February 18, the RAF said. All 18 aboard were rescued without major injuries.
BP, which operates the offshore drilling platforms, will consult the Civil Aviation Authority about whether to ground their helicopters after the two accidents, said Bernard Looney, managing director of BP North Sea.
The cause of the latest crash was not clear, authorities said, noting that they had not yet recovered the wreckage of the craft. They did not say whether it sent a distress signal before going down.
British Prime Minister Gordon Brown expressed sympathy for the families of the victims, who were believed to be on their way to Aberdeen.
"It's times like this that we remember the risks and the dangers that people have to undergo working to meet our energy needs," he said in a televised statement. "My thoughts are with the families ... and all those who are trying to help those who are in difficulty."
CNN's Per Nyberg contributed to this report.