More than 75 percent of the incidents occurred in the country's central Mopti region, Rupert Colville, UN human rights spokesman, said .
He added that the civilians were killed in 99 incidents of communal violence since the start of the year, with more than half of the killings taking place after May 1.
Earlier this month, Dogon fighters allegedly killed 16 Fulani civilians during a raid on a village, with some reportedly shot inside the local mosque and others burned alive in their houses, Colville said.
Fulani fighters and an al-Qaeda-linked armed group with close ties to Fulani communities have in turn targeted Dogon and Bambara civilians, he said.
The al-Qaeda-linked group's exploitation of ethnic tensions to win recruits and use of Mali as a launch pad for attacks into neighbouring Niger and Burkina Faso has alarmed former colonial power France and the United States, who have deployed thousands of troops to the region.
France intervened in Mali's desert north in 2013 to drive back armed groups who were threatening to march on the south's main population centres. The fighters have since regained a foothold in the north and semiarid centre.
Malians head to the polls on July 29 for a vote meant to draw a line under six years of political unrest, armed attacks and ethnic clashes. But the situation has degenerated in recent months and spilled over into neighbouring countries.
Mali's government has repeatedly said the polls, in which incumbent President Ibrahim Boubacar Keita is seeking re-election, will go ahead as planned, but the relentless violence threatens to significantly depress turnout.
