U.S. federal authorities cautioned local law enforcement on Friday to be aware that supporters of Islamic State have been calling for their sympathizers to attack holiday gatherings in the United States, including churches, a law enforcement official said.
The warning, issued in a bulletin to local law enforcement, said there were no known specific, credible threats.
The notice from the Federal Bureau of Investigation and Department of Homeland Security was issued out of an abundance of caution after a publicly available list of U.S. churches was published on pro-Islamic State websites.
“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,” the bulletin said. The notice describes different signs of suspicious activity for which police should be alert.
U.S. State Department issued a travel warning for all of Jordan because of “threats from terrorist groups” after recent deadly attacks.
It said Islamic State (ISIS) and its affiliates “continue to plot assaults” in Jordan.
More than a dozen people, including a Canadian tourist, have been killed in attacks in Jordan since last week.
The department also warned of similar threats to US citizens in Egypt, after a series of attacks there.
It advised to avoid travel to the Sinai Peninsula and the Western Desert regions.
In a statement on Friday, the department said that “terrorist and extremist organisations have expressed a desire to conduct attacks targeting US citizens and Westerners in Jordan”.
“Within the last year, Jordanian authorities have notified the US Embassy of several disrupted terrorist plots targeting US citizens and Westerners,” the travel warning added.
The jihadist group ISIS said it was behind last Sunday’s attack in the central town of Karak – the deadliest assault in recent days.
Seven members of the Jordanian security forces, two local bystanders and a Canadian tourist were killed in the attack.
It began when a police patrol received reports of a fire in the village of Qatraneh, about 32km (20 miles) east of Karak.
Officers who responded came under fire from inside the house. Two were wounded before the assailants fled in a car towards Karak castle, a major tourist attraction that dominates the town.
The stand-off there lasted several hours.
Jordan is seen by the US as a key regional player in battling ISIS fighters.