The number of girls around the world who are married off illegally every day is in excess of 20,000, with child marriage often lying at the crux of many of those unions despite being outlawed in a growing number of countries, Reuters reports.

Roughly 7.5 million girls annually become child brides in nations where early marriage has been banned. The findings come as part of a report executed by the World Bank and global charity Save the Children. It also revealed that more than 20 percent of the girls affected reside in West and Central Africa. These regions see an average of 1.7 million illegal child marriages per year, which, according to the report, are the highest rates in the world.

The results of the study point to the challenges of enforcing anti-child marriage laws because the practice can often be entrenched in community traditions and religious customs.

“Laws banning the practice are an important first step. But millions of vulnerable girls will continue to be at risk unless child marriage is tackled head on,” Helle Thorning-Schmidt, head of Save the Children, said in a statement. “We need to change attitudes in communities so that we can end this harmful practice once and for all.”

The results of early marriage are crippling. Not only does the practice deprive young girls of their right to education and job opportunities, but it also increases the risk of serious childbirth injuries or death if they have babies before their bodies are fully developed. Child brides are also more susceptible to domestic and sexual violence.

According to researchers, poverty is often the driving force behind child marriage. Parents may marry their daughters off because they will receive a “bride price” for her and it’s one less mouth to feed.

Some communities believe child marriage is a way of protecting young girls from having premarital sex.

Approximately 15 million girls are married off as children every year across the world.