At least 21 people were killed, 40 wounded and dozens of houses burned in weekend attacks aimed at Hutus in eastern Democratic Republic of Congo, which has been the scene of heightened ethnic tensions in recent weeks.
The United Nations said Monday it was "alarmed by reports of escalating inter-communal violence" in the area.
U.N. spokesman Amouzoun Codjo Martin said the weekend attacks were carried out by members of two militias, the Nande-dominated UPDI and the NDC, which is mostly made up of Nyanga, another local ethnic group.
"We have also received reports of massive displacement of civilians, looting, abductions and of at least three rapes during the past few days," the U.N. statement said.
Ethnic rivalries, foreign invasions and competition for mineral-rich land have stoked persistent conflict among eastern Congo's dozens of rebel groups over the last two decades, costing millions of lives.
Tensions have spiked between the Hutu and neighboring communities since Congo's army launched a military offensive last year against the FDLR, displacing large numbers of fighters and Hutu civilians.
Congolese troops and U.N. peacekeepers were forced to fire into the air last Wednesday in a nearby town to disperse Hutu and Nande villagers after the two groups clashed with machetes and batons.
Some information for this report provided by Reuters.