Officials in Italy are searching for answers in the suspicious deaths of 26 Nigerian women whose bodies were found at sea.

According to BBC reports, investigators are looking into the possibility that women were sexually assaulted and murdered as they attempted to cross the Mediterranean aboard a migrant boat with 375 others. The majority of the deceased women found on the boat were teens between the ages of 14-18, all of whom were believed to be traveling by way of “people-smuggling gangs.” The gangs reportedly charge migrants up to $6000 to get to Italy, with many migrants claiming that they’re subjected to sexual abuse, torture and other violence at the hands of the gangs during the trips.

The surviving passengers aboard the boat included migrants from Ghana, Nigeria, Senegal, The Gambia, Sudan and Libya.

Investigators are reportedly questioning 5 migrants in Salerno — a city in southwestern Italy—to gain information that could possibly help them determine what happened to the 26 women.