The latests killings were part of a cycle of unrest between the Hema and Lendu communities in the northeastern province, the government told AFP.
"We have counted 49 bodies and are still searching for other bodies," said Alfred Ndrabu Buju from international Catholic charity Caritas.
"A child was admitted this morning in Drodro general hospital, with an arrow in his head," Buju added.
The Interior Minister Henri Mova earlier put the death toll at 33.
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The violence happened in the village of Maze, some 80 kilometres north of Bunia, Ituri's provincial capital.
Witnesses told AFP the attackers were members of the Lendu community.
"The attackers went into the village and committed a real massacre," local activist Banza Charite said.
The violence in Ituri has left over 100 people dead since mid-December, and forced 200,000 people to flee their homes.
More than 28,000 of the displaced have fled across the border to Uganda in recent weeks, according to UN figures, most of them women and children, bringing with them tales of horrific violence.
But in the late 1990s and early 2000s their fight became a broader, more brutal battle stoked by Rwanda and Uganda, which were eager to seize gold, diamond, timber and influence as part of a wider continental war that played out inside Congo's borders.
This year's resurgent violence in Ituri is part of a patchwork of unrest in a country suffering from growing insecurity.
New conflicts are erupting as President Joseph Kabila struggles to maintain his grip on power two years after the legal end of his second presidential term.
Conflict has also erupted in the central region of Kasai, after a tribal chieftain known as the Kamwina Nsapu, who rebelled against President Joseph Kabila's regime, was killed in September 2016.
As the violence spirals, UN aid officials have said donor countries will meet in April for a conference aimed at raising nearly USD 1.7 billion for humanitarian work in the country.
The estimate of funding needs has doubled since last year, reflecting the mounting number of problems.
"We are facing emergencies and crises that are directly affecting the population," Julien Harneis, UN deputy humanitarian aid coordinator, said on Thursday.
The crisis in DR Congo, it warned, had reached a "breaking point".
The country has around 10 million people in need of humanitarian aid, of whom 4.5 million are people who have had to flee their homes because of conflict.
Three UN agencies -- the World Food Programme (WFP), children's agency UNICEF, and Food and Agriculture Organization (FAO) -- estimated in January that 3.2 million people in Kasai were facing severe food shortages.