Around 90,000 people have been displaced due to violence in Papua New Guinea since May this year.
The incidents in the country's Highlands Region flared up during elections held in July.
"Women and children are the most affected," Themba Kalua, the UN Resident Coordinator in the South Pacific Island nation, told Australia's ABC news.
He said over 25,000 students remain affected as schools are closed in the region.
The UN official said 70 women and girls were kidnapped and raped.
Another official said people do not feel safe to return home as many homes have been burnt down.
"Before July's general election, violence began in Papua New Guinea in May and continued through August with clashes during the days-long period of the election being most severe," the UN had said earlier this month.
Access to several locations was restricted while food, water and sanitation, shelter, health, and protection were most needed.
The violence is directly related to the general elections in most areas, the UN said, adding that long-standing issues, including land disputes, retribution, and unsettled disputes between clans, also reignited conflicts during the time of instability.
"Affected communities are reporting injuries, deaths, damage to food gardens, destruction of property, displacement, and disruption of education services."
