 The logistics of the referendum were organised and supervised by Diệm 's brother and confidant , Nhu , who was the leader of the family 's secret Cần Lao party , which supplied the Ngôs ' electoral base . Reports of violence and intimidation were widespread . During the referendum , Nhu 's staff told voters to throw away the green ballots . Those who disobeyed were often chased down and beaten , with pepper sauce and water sometimes being forced into their nostrils . The violations were particularly flagrant in central Vietnam , a region over which another of Diệm 's younger brothers , Ngô Đình Cẩn , ruled . Cẩn was based in the former imperial capital city of Huế , home of the Nguyễn Dynasty and a source of support for Bảo Đại . He stifled this support by ordering the police to arrest 1 @,@ 200 people for political reasons in the week leading up to the vote . In the city of Hội An , several people were killed in election violence on the day of the poll . Voting started at 07 : 00 and ended at 17 : 00 . 
