FILE - In this file photo taken Thursday, Nov. 28, 2013, an Afghan man carries an injured boy to a hospital after two roadside bombs struck the Achin district of Jalalabad, east of Kabul, Afghanistan. The number of children killed and wounded in Afghanistan’s war jumped by 34 percent in 2013 as the Taliban intensified armed attacks across the country and continued to lay thousands of roadside bombs, according to a U.N. report Saturday, Feb. 8, 2014. (Rahmat Gul, File/Associated Press)

Civilian casualties in Afghanistan rose last year as attacks by Taliban insurgents increased and women and children were caught in the crossfire, according to a U.N. report released Saturday.

The report, prepared by the U.N. Assistance Mission in Afghanistan, documents a spike in violence that is likely to exacerbate concern about the country’s security as most remaining U.S. and NATO troops prepare to withdraw this year.

According to the United Nations, 2,959 civilians were killed in Afghanistan in 2013 and 5,656 were injured. The number of fatalities jumped 7 percent compared with 2012 and fell just short of the record 3,021 civilians killed in the Afghan war in 2011.

Women and children appeared to be particularly vulnerable, with casualties up by about a third as clashes between the Afghan army and insurgents intensified in civilian areas.

The report, which the United Nations has issued annually since 2007, comes amid growing uncertainty about Afghanistan’s future as the country prepares to elect a new president and the more than 12-year-long war draws to a close.

Despite efforts by the Obama administration to leave a residual force after this year, Afghan President Hamid Karzai has refused to sign a long-term security agreement that would allow up to 15,000 foreign troops to remain into 2015. U.S. officials have said that up to 10,000 of those troops could be American.

Many analysts contend that Karzai, whose relationship with the U.S. government has soured dramatically in recent years, is pushing the matter off to his successor, who will be elected this spring.

But if an agreement is not signed soon, President Obama could opt for a full withdrawal this year. If that occurs, many analysts fear, the Afghan army will be unable to prevent even more bloodshed next year.

Already, the fledgling national army and Afghan civilians are coming under increasing attack.

The United Nations concluded that 74 percent of civilian deaths and injuries were caused by “anti-government elements,” including the Taliban and Islamist militant groups such as the Haqqani network.

It also found that the militants’ weapon of choice remains roadside bombs and other explosive devices, which were responsible for 34 percent of all civilian casualties, including the deaths of 192 children.

In a statement, the Taliban dismissed the report, suggesting that it was “drafted by the U.S. Embassy under the name of the United Nations.”

But the international coalition released a statement saying it “welcomed” the report, adding that it validates the view that insurgents cause “the overwhelming majority of civilian casualties.”

In recent weeks, Karzai has repeatedly accused the U.S. military of causing civilian deaths, including that of a 2-year-old boy killed by a suspected U.S. drone in late November. Coalition officials appeared to use the U.N report to push back at Karzai, saying that it closely tracks with internal statistics that show the Taliban is the biggest threat to civilians in Afghanistan.

“The Taliban continue to attack mosques and healthcare facilities, they target schools by burning them down, placing IEDs near them, and occupying them for insurgent activities,” the coalition statement said. “These persistent actions, including increased violence against women and religious elders, demonstrate the Taliban’s continuing disregard for human life and detract from Afghan and international community efforts to improve Afghanistan’s future.”

The increase in civilian deaths demonstrates the “changing dynamics of the conflict” as Afghan troops stepped into leading combat roles while coalition air and ground support diminished, the report states.

The shift on the battlefield gave anti-government elements in some areas “greater mobility and capability to attack Afghan security forces, the latter more active and more exposed to attacks than in previous years,” it concluded. That led to the deaths of 50 children in crossfire, the report said. “Ground engagements” caused the deaths of 73 women, it said.

And although the United Nations pins much of the blame on the Taliban and other insurgent groups, the report raises questions about the conduct of the Afghan army, noting a 59 percent increase in civilian casualties caused by “pro-government forces” engaging in reckless firing and shelling.

“Afghan security forces’ lead responsibility for security brings with it increased responsibility for civilian protection,” said Ján Kubiš, the U.N. secretary general’s special representative for Afghanistan.

Sayed Salahuddin contributed to this report.