All American Peace Corps Volunteers posted to the Upper West region have been withdrawn.The evacuation according to the United States Embassy follows the murder of an alleged robber in Wa by one of the volunteers during a mugging incident.A second robber said to have been involved is currently at large.An emergency message sent to American citizens in the country says the withdrawal until further notice is to ensure the safety and well-being of all Peace Corps Volunteers.It adds that the security situation is being monitored closely by U.S.Government officials and that all U.S. citizens in the Upper West Region should exercise caution and defer unnecessary travel in or to the area.The Country Director of Peace Corps in Ghana, Mike Koffman told Joy News the volunteers will stay away for as long as is necessary but will never abandon the region entirely.