Women and girl refugees coming into Europe face violence and sexual harassment at every stage of their journey, according to a new report from Amnesty International.

The report released Monday by the human rights group was based on interviews with 40 women and girls in Germany and Norway last month who had traveled from Turkey to Greece and then across the Balkans.

Women and girls traveling alone or accompanied only by children said they felt particularly under threat in Hungary, Croatia and Greece, where they were forced to sleep alongside hundreds of male refugees. Those interviewed included female refugees from Iraq and Syria.

The vast majority of the refugees streaming into Europe are men, which leaves women particularly vulnerable, aid workers say. Women at camps reported having to use the same bathroom and shower facilities as men, and some said they did not eat or drink to avoid going to the toilet.

The Amnesty International report did not separate out incidents of sexual harassment from general violence. One 22-year-old Iraqi woman told Amnesty International that a uniformed security guard in Germany offered her clothes in exchange for spending time alone with him.

Some aid workers say violence is harder to prevent because of an ad hoc system for receiving and registering refugees.

"One of the challenges we have been facing is that it is taking a long time for the international community, and by that I mean governments, to wake up to this crisis and to realize that it is not something that they can wish away," said Jenny Becker, protection coordinator with the International Rescue Committee in northern Lesbos in Greece.

In October, the International Organization for Migration (IOM) on Tuesday called on governments to more closely monitor sex trafficking and lend specialized assistance to the 1.5 million refugees expected to enter the European Union this year, warning of a surge in sexual assault against women being smuggled across the Mediterranean Sea from West Africa.

The IOM reported that tens of thousands of people continue to pour into Europe each day, but the group expressed particular concern for the fate of women.

Roughly 13 percent of refugees traveling toward Europe are women, according to the United Nations. Of those, some 4,200 are estimated to be pregnant and another 1,400 "at risk of sexual violence."

Al Jazeera and The Associated Press