The Department of Justice on Tuesday filed lawsuits to revoke the U.S. citizenship of five immigrants who pleaded guilty to sexually abusing minors in incidents determined to have taken place before they became naturalized, Fox News has learned.

These individuals, according to the Justice Department, “unlawfully procured their U.S. citizenship by concealing sexual abuse of minor victims during the naturalization process.”

“Committing fraud in any immigration matter undermines the integrity of our immigration system, and is a betrayal of the American people’s generosity,” Attorney General Jeff Sessions said in a statement. “It is especially appalling when it also involves the sexual abuse of children.”

The lawsuits were filed in the Southern District of Florida, the Northern District of Illinois, the Northern District of Texas and the Southern District of Texas.

According to the Justice Department, the citizenship of a naturalized U.S. citizen can be revoked under the Immigration and Nationality Act if naturalization was illegally procured through the concealment of information.