The Catholic Church has initiated an investigation after two nuns returned to Italy pregnant after completing a missionary trip in Africa.

According to Italian outlet ANSA, the two unidentified nuns - who are from Africa and had taken vows of chastity - belong to different holy orders in Sicily, one in Ragusa and the other in Militello.

One of the women is 34 years old and only realized she was pregnant after going to the hospital for stomach pain. She was then transferred to another order in Sicily. She may leave her order to raise her child, according to ANSA.

The other woman is a mother superior, or head of a female religious community. Her age is unknown. She reportedly left Sicily when she was one month pregnant and returned to her home country of Madagascar.

According to a church source in Rome,“There is consternation at this news. It appears that both women were back in their home nations and obviously had some form of sexual encounter,” the Sun reported.

“An investigation has been launched. They both breached strict rules of chastity, but the welfare of their children is uppermost,” the source added.

“The most likely outcome is they will leave their religious service.”

Earlier this year, Pope Francis admitted that nuns are frequently sexually abused by clerics. In May, the pope ordered all members of the clergy to report any allegations of sexual abuse committed by church leaders. The new legislation came after Pope Francis accepted the resignation of Cardinal Ricardo Ezzati, the archbishop of Santiago, who is accused of covering up sexual abuse committed by Catholic clergy members in Chile.