World Bulletin / News Desk
Residents of Rusaka commune in central Burundi found the grave on Tuesday, a local governor said.
"The macabre discovery took place on Tuesday at a construction site where a training center is being built," Jean Marie Nyakarerwa, governor of Mwaro province.
He added it was still difficult to determine the exact number and identity of the bodies in the grave.
Jean-Louis Nahimana, president of the National Commission for Truth and Reconciliation, told reporters on Wednesday his institution would visit the site to collect more information.
The mass grave dates back to 1972 when a major conflict took place between Hutus and Tutsis, the two main ethnic groups in Burundi, according to local residents.
In 1972, ethnic violence led to the deaths of more than 200,000 people over a period of three months, mainly members of the Hutu majority.
The violence reached another peak on October 1993 following the assassination of Melchior Ndadaye, the first democratically elected Hutu president. That violence led to the deaths of more than 300,000 people.
During the first 50 years of independence in Burundi, over 500,000 Hutus and 100,000 Tutsi were killed in mass atrocities, according to the Combat Genocide Association.
In neighboring Rwanda more than 800,000 people were killed in a genocide against the Tutsi population by Hutu extremists in 1994.