The remains of 12 people were found in the grave in February 2016.
LIBREVILLE - A court in the Republic of Congo jailed three soldiers for three years for "mass murder" during a peacekeeping mission to the Central African Republic, but the convicts have been freed, Human Rights Watch said Tuesday.
"The sentences deny justice to the victims, who included women and children," the New York-based NGO said in a statement, protesting that the jail terms "do not reflect the gravity of the crime."
Human Rights Watch only gained access to the court ruling in July, after it was handed down on April 25, and stressed that the three men "are now free, having served most of the sentence."
In March 2014, a dozen civilians went missing at Boali in strife-torn CAR, after a clash between local anti-Balaka militias drawn mainly from the Christian population and troops of an African Union mission known as MISCA. That force was later replaced by the current UN mission MINUSCA.
Two years after the trouble, a mass grave was found near a former MISCA base at Boali and international pressure was placed on Congo to see that an investigation took place.
The remains of 12 people were found in the grave in February 2016 and all were eventually identified as individuals detained by Congolese MISCA troops after the altercation with the anti-Balaka forces, in which a peacekeeper was killed.
"The authorities in the Republic of Congo missed an opportunity to provide justice for the murders of civilians and to show that no peacekeeper is above the law," said Lewis Mudge, Africa senior researcher at Human Rights Watch.
"Giving the soldiers who committed murder little more than a slap on the wrist sent a damaging message to other peacekeepers that they risk little if they commit such crimes."
In April, the appeals court in the Congolese capital Brazzaville consisted of judges and jurors who were handling the case with regard to its classification as war crimes and crimes against humanity, HRW said.
"What kind of justice is this?" a Central African family member asked Human Rights Watch. "The Congolese judges must explain how the murderer of my brother is free after only three years of detention."
The NGO noted that the entire Congolese contingent was repatriated by the United Nations in July 2017, after other documented instances of killings and human rights abuses.
It urged the African Union to publish an internal report into the Boali incidents and urged the continental body to press Congolese authorities for details of the reasoning behind the lenient sentences.
A special criminal court was created in 2015 to try war crimes and crimes against humanity in the CAR since 2003, year of a successful coup. Its investigations are due to begin in the second half of 2018.