Insurgents attacked eight oil pipelines in southern Iraq late Wednesday, temporarily slowing production of the country's most important export on Thursday, according to an official with the state-owned oil distribution company.

The attacks targeted a cluster of pipes that link a southern oil field with a pumping station in Zubair, a suburb of the port city of Basra, said Ahmed Hasan, of the Oil Products Distribution Co. The damaged pipes were part of a network of 10 distribution systems that connect the Rumaila oil fields to the pumping station, Hasan said. Other systems were not touched.

Hasan said the sabotage did not appear to be serious because the attacked cluster was used primarily to back up other delivery systems. There were conflicting reports Thursday about the impact of the attack on exports from southern Iraq, where more than two-thirds of the country's oil is produced.

A top oil official, speaking on condition of anonymity, told the Associated Press that the damage cut the day's exports to 1.2 million barrels, down from a daily average of about 1.85 million barrels. But an oil terminal manager in Basra, who also spoke on condition of anonymity, told Bloomberg News that exports had almost totally recovered by Thursday afternoon.

Any disruption in Iraq's ability to export oil, however, reduces the revenue available to fund reconstruction and revive the economy. Since the U.S.-led invasion last year, Iraq has lost an estimated $2.7 billion in revenue from sabotage of the oil infrastructure, Oil Minister Thamir Ghadban told the Reuters news agency last week. The Oil Ministry has reported more than 130 attacks between March 2003 and June of this year.

The now-disbanded U.S.-led occupation authority helped create an oil security force made up of 14,000 Iraqi police officers, but it has not been able to prevent sabotage. In fact, attacks on the pipelines have increased in the past three weeks, as Shiite Muslim militiamen loyal to rebel cleric Moqtada Sadr threatened to strike the oil infrastructure if U.S. military forces did not leave the holy city of Najaf. On Aug. 19, insurgents set fire to the headquarters of the state-owned Southern Oil Co. in Basra.

Disruption of exports from Iraq, the Middle East's fifth-largest oil producer, have contributed to sharp increases in world oil prices in the past year. Last week, the Shiite militia's threats alone helped push up prices on the New York Mercantile Exchange, where a barrel of oil reached a high of $48.70.

On Thursday, however, benchmark U.S. crude for October delivery closed at $43.10 per barrel on the exchange, down for the fifth day in a row.

Staff writer Justin Blum in Washington and special correspondent Emad Hasan Zainel in Basra contributed to this report.

Iraqi firefighters arrive at the scene of burning pipelines near Basra. The pipelines link a major southern oil field and a pumping station.