KABUL (Reuters) - Civilian casualties in religious attacks in Afghanistan, primarily against Shi ite mosques, have significantly increased in the last two years, according to the United Nations. Some 850 casualties, of which 273 were fatal, have been recorded by the U.N.'s Assistance Mission to Afghanistan (UNAMA) since the beginning of last year in more than 50 incidents, nearly double the figure for the previous seven years. (goo.gl/93CjrE) The latest attacks took place three weeks ago at two Shi ite mosques, one in Kabul and the other in the central province of Ghhor, killing at least 72 people. Islamic State claimed responsibility for them and a string of others across the country in recent months. Sectarian violence has been relatively rare in Sunni-dominant Afghanistan, but since 2015 Islamic State has escalated fears by killing scores of Shi ites. The minority Shi ites accuse the government of ignoring their needs. UNAMA recommended further action by the Afghan government to protect people and places of worship from attack. 