KABUL – Ten children, part of the same extended family, were killed by a US air strike in Afghanistan, along with three adult civilians, the United Nations said on Monday.The air strike early on Saturday was part of a battle between the Taliban and the combined Afghan-US forces that lasted about 30 hours in Kunduz, a northern province where the Taliban is strong.The children and their family had been displaced by fighting elsewhere in the country, the UN Assistance Mission in Afghanistan (UNAMA) said in releasing its preliminary findings about the incident. UNAMA said in a statement that it is verifying that all 13 civilian casualties occurred around the time of the air strike.Three other civilians were injured. The incident happened in the Telawka neighborhood near Kunduz city.Sgt. Debra Richardson, spokeswoman for the NATO-led Resolute Support mission in Afghanistan, confirmed on Sunday that US forces carried out the air strike. She said the mission aims to prevent civilian casualties, while the Taliban intentionally hides among civilians.A record number of Afghan civilians were killed last year as aerial attacks and suicide bombings increased, the United Nations said in a February report. Child casualties from air strikes have increased every year since 2014.Fighting has accelerated during a period of recurring talks between US and Taliban officials aimed at ending Afghanistan's 17-year war.