FBI warns of foreign actors trying to 'sow discord' in the wake of mass shootings This comes after another attempt on a church in Pittsburgh

Houses of worship remain a vulnerable target for attacks and foreign entities could be looking to "sow discord" using the internet, an FBI official warned at a security event with law enforcement officials and faith leaders this week.

The official, who spoke on the condition of anonymity, urged faith leaders to have a share information with U.S. authorities and to have a "strategic perspective" in thinking about security.

"You need to be thinking about this for the next six months. You need to be thinking about this for the next year. What are the consequences of going to conflict with Iran and Hezbollah, those actors of interest here," the official said.

"You need to be thinking about that right now," the official said.

The briefing covered a broad range of topics including best practices on how to keep houses of worship safe in an ever-present threat environment.

"Clearly foreign disinformation efforts are intended to do more than interfere in our election," John Cohen, the former undersecretary of the Department of Homeland Security and an ABC contributor, said in an interview after the event. "They are seeking to inspire violent attacks in the United States."

On Wednesday, the Department of Justice announced the arrest a Syrian refugee on allegations he wanted to bomb a church in Pittsburgh, Pennsylvania.

And this week, the community of Charleston, South Carolina is remembering the nine African American parishioners murdered at the Emanuel A.M.E. Church four years ago.

The report by Robert Mueller, the special counsel, detailed how Russians sowed discord by using social media during the 2016 presidential election, and how the Russia-based Internet Research Agency used Facebook, Twitter and Instagram while adopting identities claiming to be Americans.

The U.S. Department of Justice brought charges against the Internet Research Agency in 2018.