 General Ngô Quang Trưởng , commander of the 1st ARVN Division , believed that the captives had been executed by the communists in order to protect the identities of members of the local Viet Cong infrastructure , whose covers had been blown . The exact circumstances leading to the deaths of those citizens of Huế discovered in the mass graves may never be known exactly , but most of the victims were killed as a result of PAVN and NLF executions , considering evidence from captured documents and witness testimonies among other things . 
