American oil giant Chevron has confirmed that one of its helicopters crashed into the sea while on route to an oil platform off the coast of Cabinda Province, Angola, which left four people dead and two reportedly missing. Four of those on board were of Angolan origin while two more were foreigners, though their countries of origin have not yet been released.

The incident occurred as the helicopter was making a short journey to the offshore Tombua-Landana oil platform from Malongo port on Monday 26 September at 15.23 local time. It is thought the crash happened due to poor weather in the area.

Nineteen marine vessels and three helicopters were involved in the search and rescue operation led by Angolan armed forces captain Armando Nzawisa.

"The helicopter crashed in bad weather en route to a Chevron platform," Nzawisa told AFP. He added that the bodies of the four Angolans had been recovered but the search for two foreigners was continuing, reported the Mail Online.

The Chevron company released a statement saying: "The helicopter did not reach its intended destination. It was carrying five passengers and one pilot. Extensive search and rescue activities continue for those who remain missing,", according to Reuters.

Chevron said five of those aboard were contractors and one worked for Chevron affiliate Cabinda Gulf Oil Co, said Fox News. The company has not yet said if the accident will have any impact on oil production in the region.

Along with Nigeria to the north, Angola is one of Africa's largest oil producers and ships around 1.7 million barrels a day, much of it to the Far East. The province of Cabinda, which accounts for 60% of the country's oil production, is an enclave which is divided from the rest of Angola to the north by the Democratic Republic of Congo.