Gunmen ambushed and killed the top security official for the state-run Northern Oil (search) company Wednesday, the latest of a string of assassinations on Iraq's leaders, Iraqi security forces said.

Ghazi Talabani (search) was killed as he traveled to work in the oil-rich city of Kirkuk (search), said Gen. Anwar Amin, of the Iraqi Civil Defense Corps.

Three gunmen shot at Talabani's car after his bodyguard briefly left the vehicle in a crowded market. His bodyguard was also wounded.

The security chief was the cousin of Jalal Talabani (search), the leader of one of the two main Kurdish political parties, the Patriotic Union of Kurdistan (search).

Talabani is the third official this month to be killed in Iraq in recent days. Gunmen killed an Education Ministry official Sunday, and a deputy foreign minister was slain as he went to work the day before.

It was also one of several attacks directed at the struggling country's oil sector. Saboteurs blasted two oil pipelines in southern Iraq on Tuesday, cutting its exports from the south by more than half.

Iraqi oil officials said saboteurs blasted a northern oil pipeline on Tuesday night as well but did not disrupt exports. The blast occurred in the oil fields near the town of Dibis, some 20 miles west of Kirkuk, said Mustafa Awad, an official in the Northern Oil Company. The fire was extinguished.

"This is an act of sabotage. We expect an increase in such attacks because most of the pipelines are running through uninhabited desert areas," Awad said. "The aim of such actions is to hinder Iraq's development and to harm its economy."

Reviving petroleum exports is considered critical to restoring Iraq's economy after decades of war, international sanctions and Saddam Hussein's tyranny. Repeated attacks have slowed the process of returning Iraq to the forefront of global energy markets.

Kirkuk sits on some of the world's largest oil reserves. The biggest northern oil field contains an estimated 7 billion barrels of recoverable crude, putting it in the same league as Prudhoe Bay, Alaska, during its heyday in the 1970s.

The city is also considered a difficult case in the political tangle of the new Iraq. Its inhabitants are made up of Kurds, Turkomen, Arabs and Christians. Rivalry among the three Muslim ethnic groups has led to bloodshed in recent months.