Kabul, Feb 6, The number of children killed and maimed in the Afghan war increased dramatically last year, the UN said in a report released on Monday.

In the report, the UN documented 11,418 casualties, a 3 per cent increase since 2015, including 3,498 deaths, the Guardian reported.

Child casualties rose 24 per cent -- to 923 killed and 2,589 injured -- mainly as a result of ground engagements closer to residential areas, and explosive remnants of war.

While the total number of killed marked a slight drop, the number of injured has grown 6 per cent since 2016.

"It is about time the various parties to the conflict ceased the relentless commission of war crimes and thought about the harm they are doing to their mothers, fathers, children and future generations by continuing to fuel this senseless, never-ending conflict," said Zeid Ra'ad al-Hussein, the UN High Commissioner for Human Rights.

Aside from documenting the toll, the UN numbers reflect a changing war dynamic. Since 2014, international forces have largely withdrawn from the battlefield and fighting has moved into villages and closer to cities, the report said.

The leading cause of casualties is ground engagements. The UN attributed 61 per cent of casualties to anti-government groups, chiefly the Taliban, and 22 per cent to pro-government Afghan forces.

The Taliban controls or contests 97 of Afghanistan's 407 districts, according to the Long War Journal.

The report also said battle for territory left another hazard in its wake: unexploded ammunition.

Eighty-six per cent of casualties sustained by unexploded ordnance were children, with 183 killed and 426 injured, often when collecting scrap metal, tending to livestock or playing.