The United Nations Organization for Human Rights has requested a "transparent, credible" investigation into the assassination of Black activist and Brazilcouncilwoman Marielle Franco in Rio de Janeiro Wednesday.

The Office of the High Commissioner of the United Nations Organization for Human Rights (OHCHR) urged authorities to carry out the investigation independently so that it can be considered credible, and to identify those responsible and bring them before the courts.

"We understand that the authorities will commit to conducting a full investigation of the murders that occurred in Rio de Janeiro on Wednesday night," the U.N. request states, calling attention to Franco's exemplary record as a human rights activist.

The leftist Brazil Workers' Party, or PT, said it "expresses great sorrow for the tragedy. Marielle, a combative councilwoman and activist for human rights and social equality, leaves us precariously" in the "struggle in favor of the people and a just, equitable society."

PT Congressman Wadih Damous wrote on his Twitter account that "Marielle was executed. The assassination was consummated today but it's the result of a plot forged by the barbaric nature that has taken hold of Brazil.

"Under fascism, extermination groups act in complete freedom. Meanwhile, the military intervention (in Rio de Janeiro state) search book sacks of kids who live in favelas."

A member of the Socialism and Liberty Party (PSOL), Franco was returning home from an event entitled 'Young Black People Moving the Structures' in Lapa neighborhood when, according to witnesses, her vehicle was approached by another car. At least nine bullets were fired, killing the councilwoman and her driver. Her advisor, Fernanda Chaves, who was also in the vehicle, survived the attack. Read more via Tele Sur