The United Nations Assistance Mission in Afghanistan (UNAMA) on Tuesday blamed Afghan forces for firing mortar shells that struck a market in a southern province, killing at least 23 civilians. "UNAMA's initial impartial findings indicate Afghan National Army mortars inflicted heavy civilian casualties Monday", the mission said on Twitter. "Multiple credible sources assert that the ANA fired lethal mortars in response to Taliban fire, missing intended target." Afghan officials blamed the Taliban for Monday's explosions in the Sangin district of Helmand province. jds/wat/fox