Fighters in the Democratic Republic of Congo have raped at least 40,000 women over the past six years, human rights agency Amnesty International reports.
Rape survivors are often ostracised by their communities
All groups involved in the civil war committed extreme sexual violence during the civil war throughout the east of the country, it finds.
Despite a year of peace, survivors lack adequate medical care and many are dying needlessly, the agency adds.
It accuses the new government of being "far too slow" in its response.
Only aid agencies now respond to the needs of the rape victims and they are short of medical staff, drugs and equipment, says the report entitled Mass Rape - Time of Remedies.
Aid workers are quoted as saying they have never come across so many rape victims in a war while horrific new cases of rape are reported as recently as June of this year.
Amnesty urges the DR Congo government to punish perpetrators and it calls for an expert team to be set up to assess the needs of the country's health sector.
Survivors interviewed by Amnesty gave horrifying accounts of their suffering and struggle to obtain medical care.
One woman seeking medical attention after being raped in October 2002 was stopped on the road by two soldiers:
"I told them I was sick and on my way to get medical treatment because I had been raped... They threw me on the road and raped me again.
"Since then, I am extremely ill but there is nowhere I can get treatment."
Rape victims are often afraid of having contracted sexually transmitted diseases while unwanted pregnancy also intensifies their trauma, the report says.
Figures suggest between 20-30% of patients, many rape survivors, are HIV-positive, although accurate statistics from eastern DR Congo are unavailable.
Screening for infections is difficult as there is no policy for voluntary testing and it is practically impossible for HIV patients to obtain basic drugs including antibiotics, Amnesty says.
According to DR Congo's National Aids Programme, HIV/Aids could threaten more than half the population in the next 10 years.
Many people chose not to be tested for HIV/Aids because they know they risk being rejected if they are found to be HIV-positive.
Rape survivors are often ostracised by their communities and abandoned by their husbands anyway, the report says.
Call for justice
Amnesty also finds that the judicial system offers no justice to the women.
"The DR Congo government must assume its responsibility to prevent, punish and eradicate sexual violence, and demonstrate that such behaviour is not tolerated," it says.
The report comes a week after President Joseph Kabila made a historic visit to the east of the country, which was in rebel control for much of the war.
The east still remains volatile and attempts to integrate it and rebel forces into the national army are slow to progress.
Elections are due to be held in DR Congo next year.
Amnesty appealed for rapid action to alleviate the suffering of "tens of thousands of known and anonymous victims".