Soraz spokesman Magagi Dada was quoted by private television station RTT as saying: "The refinery has broken down. That’s all I can say."

Built as a joint venture between CNPC and the Niger Government at approximately 800km east of the Niamey, the refinery has oil processing capacity of 20,000 barrels per day.

The refinery, however, failed to reach full production due to financial difficulties and slump in global oil prices.

The refinery currently processes approximately 12 to16,000 barrels per day, including 7,000 barrels for the domestic market, while the remaining are processed for exports.

A senior energy ministry official was quoted by Reuters as saying that refinery halted production for the export market over a price row, since past two months.

In July, CNPC negotiated and signed a deal with the government for the supply of crude oil to the refinery at a price of $57 per barrel, from the initially agreed price of $67 per barrel.