KABUL:The number of children killed and wounded in Afghanistan's war jumped by 34 per cent last year as the Taliban stepped up attacks across the country and continued to lay thousands of roadside bombs, the United Nations said Saturday.Overall civilian casualties were up by 14 per cent, reversing 2012's downward trend and making 2013 one of the deadliest years of the 12-year war for civilians, the UN Assistance Mission for Afghanistan said in a report.