An arson suspect faces new terrorism charges after Fort Worth police linked a series of threatening social media videos to a string of car fires south of downtown.

Police say the investigation expanded after threatening videos began circulating online, including one showing a masked man vowing mass violence. Detectives believe the video originated overseas from an extremist hate group.

Investigators say five vehicles were set ablaze between Christmas Eve and New Year's Day.

Authorities believe 17-year-old Evan Banda recorded footage of North Texas schools and sent it overseas to the extremist group, which posted the threatening videos. 

Banda was arrested last week and charged with arson, terrorism, and possession of child pornography.

Fort Worth school footage among online posts

As officers monitored related posts, they found additional threatening messages and footage of Crowley Middle School. 

The Fort Worth Police Department's Arson Unit determined the threats were connected to five arson‑related videos recorded on the city's south side.

Investigation remains active

The investigation remains ongoing.

CBS News Texas will provide additional details as they become available.