BASRA, Iraq, Oct. 15 (UPI) -- Threats to Iraq’s oil sector have turned south as a guard of a Basra pipeline was killed in a gunfight with would-be bombers.

Iraq’s northern pipeline, which ships crude to Turkey, has been the main target for those disrupting the flow of oil. Attacks have rendered it mostly useless in the past four years, though recent investment in reconstruction and protection has allowed more oil to flow from Kirkuk to Ceyhan, Turkey.

In Basra, where most of Iraq’s oil is located around and the port city where nearly all of the exports go to market from, there is little of the insurgent activity. Most of the violence is intra-Shiite Iraqi fighting, a power struggle that is dangerous but steers clear of the oil sector; the competing groups see the oil sector as a prize, not a target.

On Sunday the oil protection forces interrupted a bombing operation, Voices of Iraq reports.

“The clashes occurred during the early hours of Sunday in the district of al-Zubair and near the al-Jamei mosque, western Basra, when gunmen were trying to plant an explosive charge beneath Pipeline 14, which carries oil derivatives to most Iraqi refineries,” according to a security apparatus source who spoke to VOI on condition of anonymity.

One guard was killed and another hurt. But it also could mark a new trend in Iraq that, if successful, could cripple the entire industry of the world’s third-largest oil reserves and the country itself, which depends on the oil revenue for nearly all its budget.