During the Freedom Summer campaign of 1964 in Mississippi the three civil rights workers were found dead.
Freedom Summer constituted a 1964 voter registration project in Mississippi, part of a fight by civil rights groups including the Congress on Racial Equality (CORE) and the Student Non-Violent Coordinating Committee (SNCC) to expand black voting in the South. The goal was to increase black voter registration in Mississippi, so that, the Freedom Summer workers included black Mississippians and over 1,000 out-of-state, most of them white volunteers.
Europe and the united states
I believe that the answer to this question is Syria.
