DR Congos independent human rights commission Wednesday blamed both the government and the opposition for the deaths of 46 people, most of them by gunfire, in clashes in Kinshasa in September.
Scores more were hurt in the capital when "non-identified elements in the police" and "protesters using stolen weapons" clashed September 19 and 20 in opposition protests against President Joseph Kabila, a commission report said.
The release of the CNDH report, its first since the commission was set up in July 2015, was hailed by the European Union, a major donor to the vast resource-rich nation.
Democratic Republic of Congo has seen months of trouble ahead of the official end of Kabila's mandate on December 20, his second term in office.
He is barred from serving again but has never said he plans to step aside and last month cut a power-sharing deal with fringe opposition politician Samy Badibanga as prime minister in a move that effectively extends his term to early 2018.
The CNDH toll for the September protests, which were organised by anti-Kabila coalition Gathering, was slightly lower than the UN toll of 53 dead.
There were signs of an easing of political tension in the country this week when Tshisekedi agreed to join mediation talks headed by the country's bishops, the deputy secretary of Congo's National Episcopal Conference said.
The talks, which aim to agree on a transition ahead of April 2018 presidential elections, showed "there is goodwill all round," said Andre Masinganda.
Tshisekedi's Gathering had snubbed talks involving the authorities up until this week.
The formal talks are set to start "Thursday December 8 2016" at 10am (0900 GMT) in Kinshasa, according to a statement released late Tuesday.
However the UN mission in Congo, MONUSCO, is bracing for violence ahead of December 20, UN Special Representative to DR Congo Maman Sambo Sidikou said in New York on Tuesday.
"MONUSCO has further updated its contingency plans and is further adjusting its posture and deployment to mitigate politically driven violence and to protect civilians," he said.
Kabila came to power after the murder of his father Laurent-Desire Kabila by a bodyguard in 2001 during the Second Congo War, which ended two years later.
Elected in 2006, he went on to win a second five-year term in a 2011 vote that the opposition decried as rigged.