An incident at a Virginia prison resulted in injuries to five guards, as stated by state corrections officials. They reported that most of the attackers were members of the MS-13 gang who had entered the United States unlawfully.

At Wallens Ridge State Prison, located in western Virginia, three guards were stabbed and required medical attention, along with two others, following the incident on Friday, according to the state Department of Corrections.

The department’s press release revealed that six inmates were implicated, all convicted of violent offenses such as murder and rape. Of these, five were “verified MS-13 gang members from El Salvador in the country illegally.” The sixth inmate was noted to be a U.S. citizen associated with a different gang.

“Five of the individuals responsible for this senseless attack should never have been in this country in the first place,” Chad Dotson, director of the Virginia Department of Corrections, said in a statement. “Every single day, our officers put their lives on the line to ensure public safety. … This attack is an example of the dangers they face when they show up to work every day.”

Corrections officials gave no further details about the prison attack, citing an ongoing investigation.

The agency said three of the injured officers were treated and released the day of the attack. The remaining two were hospitalized in stable condition.

Carla Miles, a Department of Corrections spokesperson, said she did not know if the two guards remained in the hospital Sunday.