A United Nations report blaming a record loss of Afghan civilian lives last year on insurgents and the Taliban was dismissed as "untrue" by a Taliban spokesman Saturday.

Meanwhile, a commander of the International Security Assistance Force was encouraged by the report's findings on who's causing the increasing deaths, but agreed that civilian deaths must drop. The U.N. Assistance Mission in Afghanistan said civilian deaths rose to 3,021 last year, up from 2,790 the prior year.

In an e-mail sent to CNN, Taliban spokesman Zabiullah Mujahid "strongly" disputed the U.N. mission's report as "untrue."

"It has been ten years since UNAMA has started blaming our Mujahideen with such numbers and untrue figures while the invading forces are using tons of explosives every day in our country, conducting raids on civilian houses and they are killing our innocent people," Mujahid said in the e-mail.

"Unfortunately I should say that UNAMA, which is operating under the umbrella of the U.N. as a propaganda tool for the invading forces, is trying to blame Mujahideen for the majority of the killings happening in Afghanistan," Mujahid wrote.

"It is unfortunate that UNAMA is supporting oppressor Americans and other invading forces and is undermining its international reputation," Mujahid stated.

A total of 11,864 civilians have been killed in the Afghanistan conflict since 2007, the U.N. mission said.

"Afghan children, women and men continue to be killed in this war in ever-increasing numbers," Jan Kubis, the U.N. special representative for the secretary-general, said in a statement. "For much too long Afghan civilians have paid the highest price of war. Parties to the conflict must greatly increase their efforts to protect civilians to prevent yet another increase in civilian deaths and injuries in 2012."

General John R. Allen, ISAF commander, said the report showed a reduction in coalition-related civilian casualties.

"Every citizen of Afghanistan must know ISAF will continue to do all we can to reduce casualties that affect the Afghan civilian population. This data is promising but there is more work to be done," Allen said in a statement.

"The most striking -- and obvious -- component of the report is the increasing number of civilian casualties attributed to insurgents," said Allen. "IEDs are now responsible for roughly one out of three civilian casualties according to UNAMA. The death toll from insurgent attacks is much too high and deserves Mullah Omar's direct attention and action."

The U.N. report said last year's deaths are 8% more than in 2010, and double the number in 2007.

The vast majority of 2011 civilian casualties -- 77%, according to the U.N. report -- were caused by anti-government forces. The number of deaths attributable to the Afghan army and international forces declined year-over-year by 4%, to 410.

The report concludes that the higher number of casualties was due to changing tactics on the part of insurgents, including greater use of improvised explosive devices (IEDs), deadlier suicide attacks and more targeted assassinations.

IEDs alone killed 967 Afghan men, women and children in 2011. Many of the 495 victims of targeted killings were provincial and district governors, peace council members and tribal elders.

Among the most disturbing statistics: in the second half of 2011, the number of women and children killed grew by 29 and 51% respectively, compared to 2010. That is in part due to the growing use of the pressure-plate IEDs, which are indiscriminate -- such that a van carrying civilians is just as likely to set off the explosive as a Humvee.

"A piece of shrapnel had gone through his head. My son is dead, and his loss is killing me and my wife. He was the only son I had," said a man in Mazar-e Sharif, who was quoted in the report.

"My daughter is nine years old, and every day before I leave for work, she cries: 'Mama, don't go to work, I don't need to eat,' "a police officer in Herat was quoted as saying.

The U.N. report says several statements from Taliban leaders in 2011 pledging greater efforts to avoid civilian casualties "neither resulted in improved protection of civilians nor minimized civilian casualties."

While NATO can take comfort from the fact that its forces -- and its allies in the Afghan National Army -- caused fewer civilian casualties last year, it is clear that overall security for civilians has not improved. This is despite the deployment of well over 100,000 international troops across Afghanistan in 2011.