The United Nations is calling for an investigation into the deaths of 15 migrants found Friday on a beach in western Libya. Eleven of the victims were found partially burned in the charred remains of a boat. Four other bodies with injuries were found near the boat. The U.N. says the migrants’ deaths likely resulted from clashes between rival human smugglers in an area that’s frequently used as a launching point for asylum seekers hoping to reach Italy by boat. The International Organization for Migration reports at least 216 people have died attempting to cross the Mediterranean so far this year, with another 724 missing and presumed dead.