[5] Following a coup attempt in Burundi in October 1965, the Burundian Foreign Ministry ordered the expulsion of the United States Ambassador and two of his aides in January 1966 for "rightly or wrongly" being suspected of involvement.

[6] Ndenzako subsequently returned to Burundi and helped Crown Prince Charles Ndizeye plan his coup on 8 July.

[2][7] A new government was installed on 12 July under Prime Minister Michel Micombero with Ndenzako serving as Secretary of State for Diplomatic Affairs.

On 11 September, the head of the Fédération des Travailleurs du Burundi called for the execution of Ndenzako, Secretary of State for Economic Affairs Rémy Nsengyumva, and former prime minister André Muhirwa and denounced them as the "people's enemies".

When a circular repeating the message was issued the following day, a large crowd gathered in the stadium in Bujumbura in anticipation of the executions—which did not occur.