Federal prisons were sent into a nationwide lockdown Monday after two inmates were killed in a gang fight in Texas. The Federal Bureau of Prisons said in a statement that the fight broke out at U.S. Penitentiary Beaumont Monday afternoon. Two inmates were injured and two were left dead. The agency then confirmed that it had locked down prisons across the nation out of an “abundance of caution,” describing the rare move as “a temporary measure to ensure the good order of our institutions. We anticipate this security measure will be short-lived.” According to CNN, the BOP said it will continue to “monitor events carefully and will adjust its operations accordingly as the situation evolves,” but it wasn’t clear if the lockdown had been lifted as of Tuesday morning. The fight in Texas reportedly involved members of the MS-13 street gang.