The security chief for Iraq's northern oil fields has been gunned down in the latest political killing, two weeks before Iraq regains its sovereignty.
Iraq's main oil export route will be out of action for several days
Ghazi al-Talabani was shot dead in the city of Kirkuk - the third Iraqi official to be killed since Saturday.
It is another blow for Iraq's oil industry, already at a standstill after a series of attacks on pipelines.
In Ramadi, west of Baghdad, a bomb has killed nine people, including four foreigners, Iraqi doctors said.
The latest attacks came as US Deputy Defence Secretary Paul Wolfowitz was in Baghdad to discuss security issues with coalition and Iraqi officials.
The killing of Mr Talabani is the latest in a string of such attacks in the run-up to the 30 June handover of power to an interim Iraqi government.
The oil official died in a hail of bullets on his way to work. His driver was seriously wounded.
Correspondents say Iraqis involved in rebuilding the country are increasingly being targeted as the scheduled transfer of power on 30 June draws near.
Iraq's interim Deputy Foreign Minister Bassam Qubba was killed by gunmen in Baghdad on Saturday. The following day, a senior education ministry official, Kamal al-Jarrah, was shot dead.
A few days earlier, Deputy Health Minister Ammar Safar had escaped an attempt on his life, while Ezzedine Salim, leader of the now dissolved Iraq Governing Council, was assassinated in a car bomb attack last month.
Now, the escalating attacks on the oil industry are crippling Iraq's only source of independent revenue.
In other developments:
Two US soldiers were killed and at least 21 people injured in a rocket attack in the city of Balad, 75 kilometres (45 miles) north of the Iraqi capital, the US military said.
- Radical Iraqi cleric Moqtada Sadr has told his militia to leave the southern city of Najaf, the scene of frequent clashes with US-led forces in the past.
- Officials in Beirut say a Lebanese man, Habib Samour, abducted in Iraq has been freed after spending almost a month in captivity.
The key southern oil terminals are expected to remain shut down for several days following a series of bomb attacks on pipelines.
In the latest incident, saboteurs blew a hole in one of the key southern pipelines for the second time in 48 hours, an Iraqi oil source told Reuters news agency.
The attacks have cut off all crude oil all exports from Iraq's southern terminals in Basra and Khor al-Amaya, which had been handling virtually all the country's exports.
The southern terminals were exporting 1.6m barrels of oil a day, and the aim had been to increase output to 2m barrels a day by 30 June.
The shutdown will cost Baghdad nearly $60m a day, analysts said.
Benchmark oil prices edged up in both New York and London on Wednesday following news of the attacks.
A pipeline in northern Iraq was bombed on Tuesday evening, but exports had already been crippled as a result of previous attacks.
The pipeline from the oilfields around Kirkuk to Ceyhan in Turkey has barely been in operation since the March 2003 US-led invasion because of repeated sabotage.
Iraqi oil exports are still below the pre-war level, even though a 14,000-strong Iraqi guard force has been set up specifically to protect pipelines and other vital parts of the oil infrastructure.
Iraqi Prime Minister Iyad Allawi says pipeline sabotage has cost the country more than $200m in lost revenues over the past seven months.