(CNN) -- 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 that coalition forces were not to blame for the increased casualties, but agreed that civilian deaths must drop. The U.N. Assistance Mission in Afghanistan said 3,021 civilians were killed 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 10 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.
In addition to casualties, the number of Afghan civilians displaced by conflict soared last year. According to the U.N. High Commissioner for Refugees, conflict and insecurity displaced some 185,000 people in Afghanistan, a jump of 41% compared to 2010.
The U.N. report suggests that there has been a significant geographic shift in casualties. As NATO and Afghan Army units focused on the southern provinces of Kandahar and Helmand, the number of civilian casualties fell sharply in the second half of 2011.
But elsewhere -- in southeastern, eastern and northern Afghanistan -- incidents rose. The number of civilians killed in Kabul province, including in the capital itself, more than tripled largely because of several devastating suicide bombings.
The figures show that the number of casualties caused by NATO and allied night operations dropped sharply, despite the much greater intensity and frequency of such operations. That suggests better intelligence and tactics among pro-government forces. But the number of civilian killed in NATO airstrikes -- a source of friction with the government of Afghan President Hamid Karzai -- rose 9%.
Increasingly, as the transition to Afghan leadership gets underway, local security duties are being assigned to a relatively new force: the Afghan Local Police. The U.N. says it has received "mixed reports" about this entity's overall performance. While most suggested that it had improved security, there were also accounts of human rights abuses and corruption.
Altogether, the U.N. Assistance Mission concludes that "the unremitting toll of civilian casualties coupled with pervasive intimidation affected many civilians directly, and many more indirectly, by fueling uncertainty, tension and fear."
The report's authors welcome "ideas that could contribute toward peace negotiations," adding their value will be measured by reduced civilian casualties and improved security.
CNN's Tim Lister, Michael Martinez and Masoud Popalzai contributed to this report.