Taliban bombings and other attacks caused Afghan civilian deaths to soar last year to the highest annual level in the war, the U.N. said Wednesday, while deaths attributed to allied forces dropped nearly 30 percent — a key U.S. goal for winning over the Afghan people.

Insurgent attacks were mainly aimed at government or international military forces but often were carried out in crowded areas, the U.N. said in a report.

Afghans seen as supporting the government or the international community also were targeted, including community elders, former military personnel, doctors, teachers and construction workers as well as employees of the U.N. and non-governmental organizations.

"Through these actions, the armed opposition has demonstrated a significant disregard for the suffering inflicted on civilians," the report said.

The U.N. mission, which is in Afghanistan to support and bolster the Afghan government, said 2,412 civilians were killed in 2009 — a 14 percent increase over the 2,118 who died in 2008. Another 3,566 civilians were wounded.

Nearly 70 percent of the killings, or 1,630, were blamed on homicide attacks and other insurgent bombings as well as assassinations and executions. Some 25 percent, or 596, were attributed to pro-government forces, the report said. The remaining 135 deaths could not be attributed to either side but were civilians caught in the crossfire or killed by unexploded ordnance.

The number of civilians killed by pro-government forces, including U.S. airstrikes, decreased by 28 percent over the previous year, the report found. Airstrikes still killed 359 civilians, or 60 percent of the deaths attributed to pro-government forces and 15 percent of civilian deaths overall.

"This decrease reflects measures taken by international military forces to conduct operations in a manner that reduces the risk posed to civilians," it said.

The top U.S. and NATO commander in Afghanistan, Gen. Stanley McChrystal, has ordered troops to use airstrikes judiciously and take other measures to reduce civilian casualties following widespread public outrage over civilian deaths.

"The thinking in the past up until this past year was that we need to go ahead and deal with the insurgency and we will take a calculated risk in terms of collateral damage," said Kamran Bokhari, an analyst with the U.S.-based global intelligence firm Stratfor. "That has somewhat shifted where more caution is being exercised."

Still, the report found that NATO forces conducted a number of ground operations that caused civilian casualties, including search and seizure operations that often involved excessive use of force, destruction of property and cultural insensitivity, particularly toward women.

Civilian casualties have been a sensitive subject in Afghanistan, with U.S. forces frequently accused of killing noncombatants in airstrikes.

But a survey released this week found that 42 percent of the 1,534 Afghan respondents now blame the violence on the Taliban — up from 27 percent a year ago. Seventeen percent blame the U.S., NATO or the Afghan security forces, down from 36 percent a year ago. But 66 percent said airstrikes by the U.S. and international forces were unacceptable because they endangered too many innocent civilians, even though they might help defeat militants.

The survey, commissioned by ABC News, the BBC and ARD German TV, was conducted from Dec. 11 to Dec. 23 by the Afghan Center for Socio-Economic and Opinion Research in Kabul, a subsidiary of D3 Systems Inc. in Vienna, Va. The margin of error is plus or minus 3 percentage points.

Nevertheless, each new report of civilians killed unleashes raw emotions, which highlight a growing impatience among the Afghan people with coalition forces' inability to secure the nation since the war began in 2001.

President Hamid Karzai's office said the best way to prevent the killing of civilians was to let Afghan forces take the lead in operations.

"We cannot guarantee what number the Taliban kill," presidential spokesman Waheed Omar said. "We can at least bring down the number of casualties that we are causing in this war, and the number of casualties that happen unintentionally by the international forces during operations."

Nearly half of the Afghan civilian casualties occurred in southern Afghanistan, which has seen intense fighting as U.S. and allied troops seek to oust the Taliban and other insurgents, the U.N. said. It said previously stable areas, such as Kunduz province and elsewhere in the northeast, also have witnessed increasing insecurity.

Unrelenting violence, which has defied a usual lull in the winter, has highlighted concern that casualties will rise as the U.S. and NATO send 37,000 more troops to try to stabilize the country.

Bokhari, the analyst, predicted the escalation of the U.S. mission in Afghanistan would result in even more casualties.

"Civilians are going to be caught in the middle," he said. "So the numbers are going to go up."

The U.N. mission maintains a database on civilian casualties but does not break down responsibility for particular incidents other than attributing them to insurgents or pro-government forces.

It tracks the numbers with human rights teams based in 20 of the 34 provinces that investigate casualty reports on the ground, including traveling to the other provinces. It also works closely with the Afghan human rights commission, which operates in all provinces.