The mission said in a statement Thursday its peacekeepers in South Sudan have conducted more than 300 patrols across the country to "collect evidence and document abuses" in Juba, the capital, and in restive Jonglei state.
Fighting between warring parties in South Sudan has displaced more than 100,000 people since it began in December, the United Nations said.
It said 10,000 civilians are being protected by U.N. police in Bor, the capital of Jonglei state. Overall, nearly 80,000 civilians in South Sudan are sheltered at eight U.N. bases across the country.
Conflict broke out after President Salva Kiir accused former Vice President Riek Machar of trying to topple his administration. Machar, sidelined when Kiir reshuffled his Cabinet in July, denies allegations of launching a coup.
An agreement to end the hostilities was brokered by representatives from both sides during mid-January talks in Ethiopia.