BASRA, Iraq - Iraq on Saturday halted all operations at the Shuaiba refinery in Basra following the overloading of fuel oil storage tanks, according to three refinery officials.

The disruption occurred after no ships arrived at the Khor al-Zubair port to load exported fuel oil since mid-last week.

The officials, who spoke on condition of anonymity, said the backlog of fuel oil at the refinery led to the suspension of operations.

It was not clear when the refinery would resume operations, said the officials.

"Resuming operations depends on the arrival of ships to load the fuel oil, which is causing the storage tanks to overload. This process is under the control of the state oil marketer SOMO," said an official with direct knowledge of refinery operations.

The oil ministry and state-owned marketer SOMO were not immediately available for comment.

The refinery had been producing around 260,000 barrels of fuel oil per day before the shutdown, the officials said.

(Reporting by Mohammed Atti and Ahmed Rasheed; Editing by Chris Reese and Deepa Babington)