(Ecofin Agency) - A helicopter has crashed on the way to a Chevron oil platform off the Angolan coast leaving four people dead and two missing.

According to the U.S oil company, the helicopter left Malongo port in Angola's Cabinda province on Monday to make the short journey to the Tombua-Landana offshore oil platform but did not reach its destination.

“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,” Chevron said in a statement

The company added that one of the passengers was an employee while four others were contractors but did not disclose if oil production was affected by the crash or the search and rescue operation, which included 19 marine vessels and three helicopters.

The Tombua-Landana field began oil production in September 2009. The field is located in Block 14, 80 kilometers offshore Angola.

Chevron operates in Angola through its subsidiary Cabinda Gulf Oil Company Limited. The company has an interest in two concessions; Block 0, off the coast of Cabinda Province, and Block 14, in deep water. It also has an interest in an onshore LNG joint venture, Angola LNG Limited.

Angola has overtaken Nigeria as Africa's largest oil exporter twice, transporting about 1.7 million barrels per day, mostly to the Asian markets, Reuters reports.

Anita Fatunji