Michelle Hindin, an associate professor at Johns Hopkins' Bloomberg School of Public Health, who specializes in gender-based violence, said the rate could be even higher. The source of the data, she noted, is a survey that was conducted through face-to-face interviews, and people are not always forthcoming about the violence they have suffered when talking to strangers.

"The numbers are astounding," she said.

Congo, a nation of 70 million people that is equal in size to Western Europe, has been plagued by decades of war. Its vast forests are rife with militias that have systematically used rape to destroy communities.

The analysis, which will be published in the American Journal of Public Health in June, shows that more than 400,000 women had been raped in Congo during a 12-month period between 2006 and 2007.

AP