A worker for Sinopec's Addax Petroleum was missing after an oil tank exploded in Gabon, the company said.
Addax said the cause of the accident on Saturday, which occurred at the Obangue-East oil producing site, was unclear and that an investigation was underway.
The accident injured six other people, who were flown to hospital in Port Gentil and Libreville with serious burns.
Addax's two oilfields - Tsiengui and Obangue - produce about 22,000 barrels per day or about 10 percent of Gabon's total.