KABUL - A bullet struck four-year-old Ezadullah in the stomach. Maysam, 12, was wounded in the leg. Both are collateral damage in a war that last year killed or wounded nearly 11,500 Afghan civilians, according to the United Nations.

Fighting between Afghan security forces and militants, especially in populated areas, remained "the leading cause of civilian casualties" more than two years after NATO's combat mission ended, said the United Nations.

The statistics have names and faces at Kabul's Emergency Hospital where, among curtains and blankets, wounded bodies tell a tale of nearly continuous violence, increasing again after nearly four decades of conflict waged against the Afghan population.

"I was on my bike," says Maysam ruefully about being in the wrong place at the wrong time on January 10. "I was going to collect my school books when I was hit."

He was one of 78 wounded when twin Taliban blasts struck near the Afghan parliament in Kabul that also killed at least 30 in a rush-hour attack.

Ezadullah, who is crying and whimpering in the hospital despite cuddles from his 13-year-old brother, was at home in his village of Logar when a stray bullet hit him on January 22.

The conflict severely affected Afghan children in 2016, with the United Nations Mission in Afghanistan (UNAMA) recording 3,512 child casualties (923 deaths and 2,589 injured).

It is a 24 percent increase from 2015 and the highest number of child casualties recorded by UNAMA in a single year since it began its authoritative report in 2009, making children disproportionately represented in the annual toll, says UNAMA human rights director Danielle Bell.

"I'm not surprised," says Dejan Panic from the Italian NGO Emergency, which runs the medical facility in the capital. "The disaster is escalating," he says. "We had 3,400 admissions last year of which 30 percent were aged 14 or under."

In 2016, children comprised 86 percent of all civilian casualties caused by the detonation of explosive remnants of war, making it the second leading cause of child casualties after ground engagements.

"The IEDs (improvised explosive device) are becoming more and more powerful," says Panic, who has spent seven years in Afghanistan. "In 2010 we saw a lot of open wounds. These days we're seeing people arriving with both legs blown off and their abdomen severely damaged.

"It's not strange to have to carry out two or three amputations and five or six specialist surgical procedures at the same time on the same patient: vascular, plastic, abdominal."

"Unfortunately," he adds, "the Afghans are getting better in the worst possible way. These homemade bombs are made from soap, gunpowder, fertilisers made from ammonium nitrate - everything that can easily be found at the bazaar, more powerful than factory-made mines."

The handicapped face a bleak future in the wretched nation especially in the countryside, acknowledges a nurse, Sakhi Shafyi, while passing a stretcher bearing a 22-year-old woman whose lower body will remain paralysed. "Sadly only the dead see the end of war," says Panic, quoting one of the Afghan medics at the hospital.

The UN's special envoy to Afghanistan Tadamichi Yamamoto said the new figures were "deeply harrowing" and highlight "the gruesome reality of the conflict".

He called on all parties - militants as well as pro-government forces - to cease fighting in populated areas, and stop using schools, hospitals and mosques for military purposes. "The continuation of attacks targeting civilians and indiscriminate attacks by Anti-Government Elements - in particular, IED and suicide attacks in civilian-populated areas - is illegal, reprehensible and, in most cases, may amount to a war crime," the report said. "It is imperative that the perpetrators, whoever they are, be held accountable for such acts."

The report recorded the majority of civilian casualties in Kabul province followed by Helmand, Kandahar, Nangarhar, Uruzgan, Kunduz and Faryab provinces, said the mission's human rights director Danielle Bell.

The United Nations attributed at least 4,953 deaths and injuries to the Taliban, but in a shift in 2016, investigators documented a 10-fold increase in casualties caused by Islamic State militants, who often target members of the Shiite Muslims. At least 899 deaths and injuries were attributed to Islamic State, which has been a relatively minor faction in Afghanistan, but last year launched an increasing number of suicide attacks.

The UN's High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, said the emergence of Islamic State in Afghanistan was an "additional, deadly component" to nearly four decades of conflict.

About 61 percent of all civilian casualties were caused by anti-government groups like the Taliban and Islamic State.

2016 also saw the highest number yet of civilian casualties caused by airstrikes - 590, of whom 250 were killed, the report said. That is nearly double the number of 2015, with women and children in populated areas often the victims, such as near the northern provincial capital of Kunduz in October.

Afghan security forces caused about 20 percent of the overall casualties, while pro-government militias and international forces caused 2 percent each. Among the deadliest tactic used by government forces was the indiscriminate use of heavy weapons like mortars in populated areas, the United Nations said.

In the eight years since the United Nations launched the annual report, the conflict has claimed 24,841 civilian lives with 45,347 injuries, the report said. The vast majority (61 percent) of the casualties last year were attributed to "anti-government elements", mainly the Taliban, but also to the Islamic State group, while 24 percent were attributed to pro-government forces.