The blasts marked the second attack in two days; on Tuesday explosions damaged the same southern pipeline but did not hinder exports. In May, a bombing shut down exports through the northern pipeline from Kirkuk to Ceyhan, Turkey, the Associated Press reported.
"Due to the damage inflicted on the two pipelines, the pumping of oil to the Basra oil terminal has completely stopped," Southern Oil Co. spokesman Samir Jassim told the AP. "Exports have come to a halt."
Jassim said the damage would take at least a week to repair and cost the country $60 million a day in lost oil revenue. Anti-U.S. guerillas eager to sabotage the handover of power to the new interim Iraqi government are believed to be responsible for the attacks, Reuters reported.
Ongoing attacks on Iraq's oil pipelines have slowed exports from the country, which sits atop the world's second largest oil deposits after Saudi Arabia. Officials have said restoring and boosting oil exports were critical steps to rebuild Iraq's war-torn economy.
In another attack on the oil industry, gunmen killed the chief security officer for the Northern Oil Co. in Kirkuk, Ghazi Talabani, as he was being driven to work. Talabani is a cousin of Jalal Talabani, the head of one of Iraq's main Kurdish political parties. Talabani's driver was also badly wounded in the attack, according to wire reports.
"What you are seeing here is effectively a terrorist war against Iraq's critical infrastructure, including the oil infrastructure," coalition spokesman Dan Senor told CNN. "It is an effort to basically, economically, impoverish the Iraqi people."
Also on Wednesday, Muqtada al-Sadr, the radical Shiite cleric whose followers had been battling U.S. and Iraqi forces in Najaf and Karbala for the last two months, instructed members of his al-Mahdi militia to pull back and return to their homes. The stand down comes just days after al-Sadr agreed to a truce with U.S. military officials that included the withdrawal of U.S. troops from Islamic holy sites in Najaf.
The young cleric said he would begin his own political party to contest national elections scheduled prior to January 2005, according to Reuters.
Elsewhere in Iraq, a rocket attack killed two U.S. soldiers and wounded 26 others at a U.S. base near the city of Balad, 50 miles north of Baghdad, military officials said. The two deaths bring the numbers of Americans killed in combat in Iraq to 611.