Three people were killed on Thursday when a helicopter carrying eight passengers crashed off Ghana's western coast, home to the nation's offshore oil industry, the military said.
"Three people have been confirmed dead," Ghana Armed Forces spokesman M'Bawine Atintande told AFP, adding that four people have been rescued and one remained missing.
Ghana's respected Joy FM radio station reported online that five Ghanaians and three foreign nationals -- British, French and Nigerian -- were on board the helicopter, citing an official at Ghana's Civil Aviation Authority, Albert Taylor.
Atintande could not confirm the nationalities reported by Joy FM.
The spokesman said the victims were thought to be oil workers and that the helicopter may have been operated by a servicing firm that ferries people between offshore platforms and the mainland.
A spokesman for Anglo-Irish Tullow, Ken Nunoo, told AFP that none of the company's employees or contractors were involved but that Tullow was helping with the search and rescue effort.
Nunoo said employees of the Russian energy firm Lukoil were involved in the crash, but the company could not be immediately reached for comment.
Lukoil, which is engaging in exploratory drilling off Ghana's coast, is Russia's "second largest non-state (owned) publicly traded oil company," its website says.
Tullow is lead operator in the region, which produces roughly 100,000 barrels of crude per day.
American company Kosmos Oil also has a significant presence in the region.
The helicopter took off from the coastal town of Takoradi at 1250 GMT and had been scheduled to land at a platform offshore at 1310, Taylor told Joy FM.
After reports of the crash emerged, Ghanaian navy and airforce personnel launched a rescue mission that saved four of those on board, the radio station further reported.
Ghana began producing oil from its offshore fields in December of 2010 and officials have voiced hope that the country could avoid the chronic problems which have plagued other west African oil producers, especially Nigeria.
Aside from widespread corruption, Nigeria's oil sector, Africa's largest which produces some two billion barrels of crude per day, has been hindered by thousands of spills, major infrastructure breakdowns and other accidents.
Ghana has so far been broadly applauded for the management of its sector, including for the strict safety legislation it has imposed on foreign firms.
Thursday's crash is believed to be the first significant accident to hit Ghana's oil sector since production began.