"We believe there should be no impunity for the sexual and gender-based violence committed by so many -- that there must be arrests and prosecutions and punishment," she said during a press conference with Congolese Foreign Minister Alexis Thambwe Mwamba in the eastern city of Goma, according to the Associated Press.
Clinton visited Magunga Camp, where about 18,000 men, women and children fled to avoid fighting that has raged off and on for the past decade, killing more than 5 million people.
Congo has hailed a military operation against rebels groups a success, but the rebels targeted by the Congolese army and U.N. forces have killed hundreds of civilians in reprisal attacks and displaced thousands more, according to Reuters.
Watch a report from Jason Maloney of The Bureau for International Reporting about the state of U.N. peackeeping operations in Congo.
On Tuesday, residents of the camp told Clinton they were suffering from malnutrition, malaria, tuberculosis and diarrhea.
In addition, women and young boys and girls are susceptible to rape when they leave the camp to collect wood for cooking, the residents said.
The United Nations has recorded at least 200,000 cases of sexual violence against women and girls in the region since conflict erupted in 1996.
"We really want to return home, that's why we are asking America to help stop the fighting," said Chantale Mapendo, who lives in the camp, quoted the AP.
"That's why I'm here," Clinton replied. "I want you to be able to go home."
She said Tuesday that the people of eastern Congo were still suffering from a "reign of violence" at the hands of rebel groups and the national army, which in January launched a U.N.-backed campaign to pacify the region, the AP reported.
Earlier in August, Human Rights Watch demanded that Congo crack down on sexual violence, which is often reportedly perpetrated by military generals and other top officers. It cited U.N. data showing that 7,703 cases of sexual violence by soldiers were reported last year.
Rights groups have called for a suspension of the operation, which has displaced some 800,000 people and left hundreds of civilians dead.
Clinton said the United States is "very concerned about the civilian casualties, both deaths and rapes and other injuries, from the military action." But she also said the U.S. supported efforts to eliminate the threat from insurgents and said the U.S. wants the Congolese military professionalized to prevent abuses from the government, according to the AP.
Earlier in the day, Clinton sought to deliver a strong message to Congolese President Joseph Kabila when they met in a tent at a compound in Goma, on the shore of Lake Kivu. She said the United States will send a team of legal and financial and other technical experts to come up with specific recommendations for overcoming Congo's problems with corruption. She said Kabila had accepted that offer, Reuters reported.
Clinton is in the DR Congo as part of an 11-day tour of Africa.
---- Compiled from wire reports and other media sources