BAGHDAD, Iraq, Feb. 20 - Insurgent attacks to disrupt Baghdad's supplies of crude oil, gasoline, heating oil, water and electricity have reached a degree of coordination and sophistication not seen before, Iraqi and American officials say.
The new pattern, they say, shows that the insurgents have a deep understanding of the complex network of pipelines, power cables and reservoirs feeding Baghdad, the Iraqi capital.
The shadowy insurgency is a fractured movement made up of distinct groups of Sunnis, Shiites and foreign fighters, some of them aligned and some not. But the shift in the attack patterns strongly suggests that some branch of the insurgency is carrying out a systematic plan to cripple Baghdad's ability to provide basic services for its six million citizens and to prevent the fledgling government from operating.
A new analysis by some of those officials shows that the choice of targets and the timing of sabotage attacks has evolved over the past several months, shifting from economic targets to become what amounts to a siege of the capital.
In a stark illustration of the change, of more than 30 sabotage attacks on the oil infrastructure this year, no reported incident has involved the southern crude oil pipelines that are Iraq's main source of revenue. Instead, the attacks have aimed at gas and oil lines feeding power plants and refineries and providing fuel for transportation around Baghdad and in the north.
In an indication of how carefully chosen the targets are and how knowledgeable the insurgency is about the workings of the infrastructure, the sabotage often disrupts the lives of Iraqis, leaving them dependent on chugging, street-corner generators to stave off the darkness and power televisions or radios, robbing them of fuel for stoves and heaters, and even halting the flow of their drinking water.
The overall pattern of the sabotage and its technical savvy suggests the guidance of the very officials who tended to the nation's infrastructure during Saddam Hussein's long reign, current Iraqi officials say.
The only reasonable conclusion, said Aiham Alsammarae, the Iraqi electricity minister, is that the sabotage operation is being led by former members of the ministries themselves, possibly aided by sympathetic holdovers.
"They know what they are doing," Dr. Alsammarae said. "I keep telling our government, 'Their intelligence is much better than the government's.' "
Sabah Kadhim, a senior official at the Iraqi Interior Ministry, said he believed the sabotage was part of a larger, two-faceted plan that included the terror operations that have killed so many Iraqis over the last two years.
The new pattern of sabotage, he said, lays the groundwork for chaos - a deeply resentful populace, the appearance of government ineffectuality, a halt to major business and industrial activities. The second side - the suicide bombings, assassinations and kidnappings - he said, is aimed in large measure at sowing discord among ethnic and religious groups.
"And I think they, honestly, stand a better chance with the first than the second," Mr. Kadhim said.
Whatever the source of the plan, it shows clear signs of being centrally controlled, Iraqi and American officials say.
"There is an organization, sort of a command-room operation," Thamir Ghadhban, the Iraqi oil minister, said Thursday in an interview. In his area of responsibility, Mr. Ghadhban said, "the scheme of the saboteurs is to isolate Baghdad from the sources of crude oil and oil products."
"And they have succeeded to a great extent," he said.
Mr. Ghadhban supported his assertions with a map showing that in November, December and January, in widely scattered attacks, insurgents simultaneously struck all three crude oil pipelines feeding the Doura fuel refinery in Baghdad. The refinery is the nation's largest producer of gasoline, kerosene and other refined products.
During that period, more than 20 attacks occurred on a set of huge pipelines carrying things like oil, kerosene, gasoline and other fuels to Baghdad from oil fields and refineries in the north.
In contrast, in the same region, the map shows an economically crucial crude oil pipeline - one that carries oil for export - was not attacked even once.
The map was prepared by his ministry by cataloging the exact coordinates, dates and nature of the attacks and combining that information with a detailed schematic of the web of pipelines, fuel depots, roads and refineries in and around Baghdad.
Those attacks caused widespread disruptions, including severe gasoline shortages. And Mr. Ghadhban said that when he tried to make up for the shortages by trucking the fuel in with tankers, saboteurs went after the fuel convoys and the bridges that they crossed to reach Baghdad.
After allowing a reporter to view on a computer screen the map and an array of other graphs and figures describing the pattern of sabotage, Mr. Ghadhban declined to provide a copy, but his ministry's analysis has circulated among other officials in Iraq, and one of them agreed to give a copy of the map to The New York Times.
Oil and transportation are far from the only infrastructure that the insurgents have struck to isolate Baghdad and deprive its residents.
In mid-January, a bomb hit a water main from a treatment plant that supplies 65 percent to 70 percent of the city's drinking water. It struck in just the spot that would lead to a collapse of water pressure in nearly the entire system. Most Baghdad residents were left with little or no running water for more than a week.
Attacks on carefully chosen targets were also a major reason that the output of Iraq's national electricity grid recently slumped below the amount it produced before the American-led invasion in April 2003, despite billions of dollars of projects aimed at repairing power plants and transmission lines, and adding huge new electricity generators.
And although the overall output has recently reached prewar levels, that qualified success has been punctuated by repeated blackouts caused by breakdowns, sabotage and other problems.
With all of their knowledge, and a seemingly unquenchable hatred for the people now running the government, the insurgents have transformed their initially generic brand of sabotage into a more subtle science, said Gal Luft, executive director of the Institute for the Analysis of Global Security in Washington, which closely tracks Iraq's oil infrastructure.
The attacks now aim to "prolong the destruction," Dr. Luft said. Insurgents achieve that aim by going after critical junctures in the pipeline system and focusing on equipment that is difficult to repair or remanufacture - even taking into account what stocks of spare parts may be low in Iraqi warehouses, he said.
The insurgents also skillfully play on what Dr. Luft calls the "chicken-and-egg relation" between fuel and electrical power: without oil there is no electricity, and without electricity, oil cannot be pumped or refined. So an attack on one area of infrastructure can disrupt another.
With all those moves at their disposal, the insurgents have turned away from a single-minded focus on blowing up pipelines that export oil, he said.
"I feel that this is a very different approach," Dr. Luft said. "The main thing today is isolating the Baghdad area and making sure there is not enough oil going into the refineries."
That pattern has not gone unnoticed by American military and government officials.
"I do think there is a Baghdad regional plan," said Lt. Col. Joseph P. Schweitzer of the United States Army Corps of Engineers, who before moving to a new assignment this week spent seven months as director of the Reconstruction Operations Center, an umbrella organization for military and civilian infrastructure work in Iraq.
"It's a chess game," Colonel Schweitzer said. "This is a very smart, adaptive enemy."
He said he doubted that the plan was unified throughout the country, but that the observed patterns provided clues on how to fight the insurgency. "It is something that we're studying intensively, and we have been studying," he said. "We've come to some conclusions, and we're taking actions.
But a spokesman for the American-led forces in Iraq, Col. Robert A. Potter of the United States Air Force, said in a statement sent by e-mail, "It would be speculative to affirm or rebut whether or not these attacks are random or specifically aimed to cause a specific effect."
Whatever script the insurgents may be following, their attacks have been prolific, said Mr. Ghadhban, the oil minister. His ministry registered 264 acts of sabotage against the petroleum infrastructure in 2004 and more than 30 so far this year, he said.
No one tactic could turn back what amounts to a siege on the great circulatory systems of a nation, Mr. Ghadhban said. But he has already solicited contracts for a vast protection system that would include fences on both sides of pipelines stretching for thousands of miles in the desert, with infrared surveillance cameras, sensors, airborne surveillance and a nimble security force.
Whether Mr. Ghadhban will have a chance to carry out his plan as the oil minister is another question. Although he won a seat in the new national assembly, the gasoline shortages, fairly or unfairly, have hurt his public standing in this political season.
"If I'm chosen, I will continue, definitely," Mr. Ghadhban said. "And I think we would do better."