The Pennsylvania State Police last week sent out a memo to members of the agency as well as its partners about the possibility of terrorists impersonating police, fire or EMS responders to carry out an attack in the U.S.
Officials told CBS News that the alert was meant to remind law enforcement about the need to be vigilant and not directly related to Pope Francis' highly anticipated visits to Washington, D.C., Philadelphia and New York City this week.
While there are no credible known threats at this time, the official told the news outlet that the alert would apply to the pope's visit.
House Homeland Security Committee Chairman Michael McCaul last week revealed that at least one threat made against Pope Francis has been stopped. McCaul received a classified briefing from the Secret Service on the papal visit and told CBS News that the threat of lone wolf attacks is concerning.
The pope will arrive in Washington, D.C. on Tuesday where he is expected to become be the first pope to address Congress. In New York, he'll appear before the U.N. General Assembly and will wrap up his trip in Philadelphia at the 2015 World Meeting of Families.
Security for Pope Francis' visit includes screening checkpoints, airspace restrictions and a ban on selfie sticks and backpacks at events.
