Authorities have halted oil export flows from the main pipeline in southern Iraq after intelligence showed a rebel militia could strike infrastructure, an oil official said on Saturday.
The shutdown kept loadings at southern oil terminals at half their normal level, undermining the government's effort to raise revenue as oil prices hit record highs, partly in response to the instability in Iraq.
"The situation in Basra is bad. Management ordered the pipeline shut late yesterday," said the South Oil Company official, who declined to be named.
"Very few people showed up to work again today. The feeling is it is not wise to challenge Sadr's followers."
He was referring to the uprising led by anti US-cleric Moqtada al-Sadr, whose Mehdi Army militia is fighting U.S-led forces in central and southern Iraq.
The Mehdi Army has vowed to attack oil facilities in response to a US offensive on Shia city of Najaf.
The instability and damage to the main export pipeline in the south from sabotage has disrupted Iraq's oil exports through the past five days.
Only the tanker Antonius was loading on Saturday at 864,000 barrels per day (bpd) from platform number two at the Basra terminal, formerly known as Mina al-Bakr.
Flows to offshore terminals, which account for all of Iraq's exports, were running through another smaller pipeline at a rate of one million barrels per day. The larger pipeline has a capacity of 1.5 million bpd.