USviewer: As they did so, President-elect Donald Trump used Twitter to broadcast his potentially inflammatory thoughts on the truck attack on a Berlin Christmas market on Monday.
Nevertheless, U.S. law enforcement officials said there are no specific, credible threats. Instead, the bulletin was issued out of an abundance of caution given the public nature of the posted threats and the crowded gatherings expected during this holiday season.
"The FBI is aware of the recent link published online that urges attacks against U.S. churches. As with similar threats, the FBI is tracking this matter while we investigate its credibility," the FBI said in a statement.
Islamic State sympathizers "continue aspirational calls for attacks on holiday gatherings, including targeting churches," CNN quoted the bulletin as saying. The notice describes different signs of suspicious activity for which police should be alert, it said.