The FPSO Trinity Spirit, with can process up to 22,000 barrels of oil per day, was situated near Warri in southern Nigeria when it burst into flames.

The vessel, which is also used for offloading, is owned by Shebah Exploration & Production Company Ltd (SEPCOL), whose chief executive Ikemefuna Okafor said there were no immediate reports of fatalities.

Footage circulating on social media shows the vessel sinking as huge clouds of thick black smoke billow into the sky.

"We can confirm that there were ten crew men on board the vessel prior to the incident and we are prioritising investigations with respect to their safety and security," Mr Okafor said.

He added that investigations were underway to establish the cause of the explosion in the early hours of Wednesday while attempts to contain the situation were being made with help from local communities and Chevron, which has a facility nearby.

SEPCOL is in receivership, a form of bankruptcy protection.