A study by the United Nations Children's Agency has revealed that thousands of women and children trying to escape war and poverty are being beaten, starved and raped.
The UNICEF report released on Tuesday focused on refugees making the dangerous journey from Africa as they try to reach Europe.
Many cross the Mediterranean Sea between Libya and Italy.
The report found that last September, around 250,000 migrants were living in Libya, most of them in disease-ridden detention centres, which UNICEF compared to forced labour camps and described as 'living hell holes'.
It also revealed that armed groups had taken control of many detention centres, and were working with other criminal gangs to profit from people smuggling.
Many women said they had been raped and many children said they had been beaten.
According to the UN migration agency, a record 181,000 migrants crossed between Libya and Italy last year, including 25,800 unaccompanied children.
More than 4,500 people drowned.
TRT World spoke to UNICEF spokeswoman Sarah Crowe in Geneva.