FOND DU LAC, Wis. (CBS 58) -- A 15-year-old from Fond du Lac is being held at the Fond du Lac County Secure Detention Facility while police investigate online statements that referenced a potential mass shooting, Fond du Lac police say.

Police report receiving information on Monday, Oct. 26 from state and federal law enforcement officials. The report was first submitted to the FBI's National Threat Operations Center and shared with Fond du Lac police through the Wisconsin Department of Justice's Division of Criminal Investigation.

Police say the tip came from a person outside the United States who was concerned after online interactions with the 15-year-old.

Detectives served a search warrant at the teen's home on Tuesday, Oct. 27 and seized multiple firearms, a computer and a cell phone, police say. Forensic investigators are analyzing the devices. Detectives interviewed the teen again on Tuesday, Nov. 3 and county Human Services Youth Justice social workers evaluated the juvenile before placement in detention.

Police referred one count of terrorist threats and one count of disorderly conduct to Fond du Lac County Human Services Youth Justice.