The Islamic State is using several forms of contraception to maintain its supply of sex slaves, the New York Times reported on Saturday, citing interviews with more than three dozen Yazidi women who escaped from the militant group.

The New York Times reported that Islamic State used "oral and injectable contraception, and sometimes both" to ensure that the women did not become pregnant and could be passed among the fighters.

"In at least one case, a woman was forced to have an abortion in order to make her available for sex, and others were pressured to do so," the paper said.