KABUL, Afghanistan — Even with peace talks underway, the war in Afghanistan killed almost 4,000 civilians last year, including a record number of children, officials said Sunday, as both sides pursued aggressive combat operations.
It made 2018 the single deadliest year for Afghan civilians since the United Nations began documenting casualties a decade ago.
The United Nations attributed roughly two-thirds of civilian casualties — 63 percent — to insurgent groups, primarily the Taliban and the Islamic State. Afghan and American forces were responsible for 24 percent — 14 percent by Afghan national security forces, 6 percent by American forces and 4 percent by government-backed armed groups. Responsibility for the remaining casualties could not be established.
The single biggest cause of civilian casualties — 42 percent — was suicide bombings and related attacks by insurgents, the report found. The numbers of civilian casualties caused by suicide bombings and by American and Afghan government airstrikes were each the highest recorded since the United Nations issued its first report in 2009.
The numbers reflected a surge in fighting, especially last fall, when both sides in the conflict, which is in its 18th year, stepped up attacks as they sought leverage in peace talks between the United States and the Taliban.
On the insurgent side, Islamic State attacks on civilians rose 118 percent for the year, the United Nations found, while Taliban attacks on civilians nearly doubled compared with 2017.
The report was released a day before the next round of peace talks between American and Taliban negotiators, scheduled for Monday in Doha, Qatar. The Taliban refuse to negotiate with the Afghan government, which they consider illegitimate.
It was a reminder that, even as many Afghans express renewed hopes for a negotiated end to the conflict, civilians face a rising tide of threats — including from suicide bombings, ground fighting, airstrikes, Taliban rockets and what the United Nations called “the deliberate targeting of civilians” by insurgents.
According to the report, there were 3,804 civilian deaths last year, the highest total ever recorded by the United Nations and an 11 percent increase over 2017. Overall civilian casualties rose 5 percent, to 10,993, but the total was slightly below the more than 11,000 casualties reported in 2015 and 2016.
Among the dead last year were 927 children, also the highest annual total reported by the United Nations. Insurgents were responsible for 44 percent of child casualties in 2018, with Afghan and American forces blamed for 34 percent. The number of children killed in airstrikes more than doubled in 2018 compared with 2017, the report said.
In a statement, Tadamichi Yamamoto, the United Nations secretary general’s special representative for Afghanistan, called the casualty figures “deeply disturbing and wholly unacceptable.” Michelle Bachelet, the United Nations high commissioner for human rights, called the record number of children killed “particularly shocking.”
The United Nations acknowledged efforts by Afghan and American forces, and the Taliban, to protect civilians.
But the report urged the Taliban to end the use of indiscriminate bomb attacks against civilians. It called on the Afghan government and the United States to more rigorously investigate allegations of civilian casualties and to provide reparations.
In a letter included in the report, the United States military command in Kabul, the Afghan capital, said “all feasible precautions” were taken to limit civilian casualties. Any allegation of civilian casualties considered “serious” resulted in “an inquiry and formal review process,” the letter said.
The American letter listed 62 confirmed deaths and 55 confirmed injuries from American combat operations in 2018. An additional 68 deaths and 66 injuries were listed as “disputed” because of insufficient information but could be reviewed further if new information comes to light.
The letter said American forces “will continue to strive to eliminate” civilian casualties.
A Taliban letter rejected the United Nations’ findings and denied that insurgents fired from civilian areas, used civilians as cover or engaged in “indiscriminate and disproportionate” attacks against civilians using homemade bombs. Any Taliban fighter who did so was punished under Shariah law, the letter said.
The Taliban said the United Nations report had been written to cover up attacks against civilians by “foreign invaders” — the United States — and the “puppet” government of Afghanistan. “Civilian protection is our top priority,” the letter said.
A letter from the Afghan government said its tally of civilian casualties caused by Afghan forces was “significantly lower” than the numbers in the United Nations report. It said many combat operations had been canceled or delayed because of concerns about civilian casualties.
The letter said the government was “fully committed to the protection of civilian population as its paramount duty.”
Of the 674 civilian casualties attributed to American forces, 94 percent resulted from airstrikes. The record 536 civilian deaths caused by airstrikes in 2018 were more than the total deaths from airstrikes in 2014, 2015 and 2016 combined.
Civilian deaths caused by airstrikes rose 82 percent compared with 2017, and all civilian casualties from airstrikes increased 61 percent.
American aircraft dropped more than 7,300 bombs, missiles and other munitions over Afghanistan last year, up from 4,300 in 2017 and 1,300 in 2016, according to United States Air Force data. The airstrikes were part of an effort to displace the Taliban, which controls more territory now than at any time since the United States invaded in 2001.
The United Nations attributed 632 civilian casualties to American airstrikes, and 304 to the Afghan Air Force.
The pace of ground attacks ramped up as well. American and Afghan commandos more than doubled the number of joint raids conducted from September to early February, compared with the same five-month period a year earlier, military data show.
Civilian casualties attributed to Afghan and American forces rose 24 percent compared with 2017, the United Nations reported.
The report said government search operations had killed 284 civilians. It attributed many of those casualties to covert C.I.A.-backed units whose abuses were detailed in a New York Times report in December.
Insurgents also went on the offensive, carrying out an average of 1,700 attacks a month late last year, according to the Special Inspector General for Afghanistan Reconstruction, a United States agency. The United Nations said ground clashes were responsible for nearly a third of civilian casualties in 2018.
The United Nations expressed particular concern about the Taliban’s use of homemade bombs and indirect weapons such as rockets. It cited “indiscriminate effects,” whether directed against civilian targets or government and American forces in civilian areas.
The number of civilian casualties from suicide bombs and “complex attacks” — in which insurgents detonate explosives and then send in gunmen on suicide missions — was the highest ever recorded by the United Nations. Those casualties were 22 percent higher than in 2017.
The expansion of Islamic State operations in Afghanistan last year was reflected in the 2,100 civilian casualties attributed to the group, more than half the 4,000 casualties for which the Taliban were blamed.
The arrival of Islamic State militants in Afghanistan after 2014 posed a new threat to civilians, especially Hazaras, a mostly Shiite Muslim minority. The Islamic State, a Sunni Muslim group, considers Hazaras apostates and has targeted them for attack.
The only significant pause in civilian casualties last year came in June, when both sides agreed to a brief cease-fire during the Eid al-Fitr holiday.
Two large-scale insurgent campaigns contributed to high civilian casualty rates: a suicide ambulance attack in Kabul in January, and insurgent attacks against polling sites during the parliamentary election in October. The United Nations said nearly half of all insurgent suicide bombs and complex attacks in 2018 took place in Kabul.
Since 2009, the United Nations has reported 32,000 civilians killed and 60,000 injured.
“In addition to the lives lost, the dire security situation is preventing many Afghans from enjoying their economic, social and cultural rights, with thousands of children already handicapped for life because of attacks on schools and medical facilities,” Ms. Bachelet, the United Nations official, said in a statement.