The UN estimates 3,500 women have been raped since the start of the year
US Secretary of State Hillary Clinton has demanded an end to widespread sexual abuse in war-ravaged eastern DR Congo, during a visit to the country.
Mrs Clinton spoke out during a tour of a crowded refugee camp in the eastern city of Goma.
Earlier, following talks with Congolese President Joseph Kabila, she said there should be no impunity for the perpetrators of sexual violence.
The UN estimates 3,500 women have been raped in DR Congo so far this year.
And in a report released to coincide with Mrs Clinton's visit, the aid agency Oxfam said it had monitored 20 communities and found that children, some as young as four, had been raped in half of them.
Men have also been the victims of rape, Oxfam said.
'Arrest, prosecute, punish'
The BBC's Will Ross, in Nairobi, says perpetrators go unpunished and that sexual attacks have increased since January, when a government offensive was launched against rebels linked to Rwanda's genocide.
The UN says sexual crimes have been carried out by both militia fighters and government troops.
Mrs Clinton, who is on a seven-nation African tour, said she had "a very frank discussion" with President Kabila on sexual violence.
"We believe there can be more done to protect civilians while you are trying to kill and capture insurgents," she said.
"We believe there should be no impunity for the sexual and gender-based violence committed by so many and that there must be arrests, prosecutions and punishments."
She said that Mr Kabila had agreed to allow a team of US legal and technical experts to make "specific" recommendations on how to combat sexual violence.
More than four million people were killed in DR Congo between 1998 and 2003, when armies from several countries fought each other on Congolese territory.
Rape was widespread during that war, and troops and rebels have continued to abuse women and children as violence has resurfaced over the past six years.
Leah Chishugi, a campaigner on behalf of rape victims in DR Congo, says Mrs Clinton should urge UN troops already in the country to do more to protect women.
She says sexual violence is helping to spread HIV.
"I came across a woman who said she was with her children in her house - they were 12 and 14," she told the BBC's Network Africa programme.
"She begged the rebels to rape her children first and finish with her because she had HIV/Aids. But she was crying because they didn't listen."
After DR Congo, Mrs Clinton will travel to Nigeria. Her final stops are Liberia and Cape Verde before returning to Washington on 14 August.