Around 61 migrants were missing and presumed dead after their boat sank off Libya's coast, the International Organization for Migration (IOM) said Saturday, in the latest migrant tragedy off North Africa. The "large number of migrants" are believed to have died because of high waves which swamped their vessel after it left from Zuwara, on Libya's northwest coast, the IOM's Libya office said in a statement to AFP. Citing survivors, it said there were about 86 migrants aboard.