Multiple people set on fire in what FBI calls "targeted terrorist attack" in Boulder, Colo.

Multiple people were burned, some severely, in an attack Sunday on Boulder’s Pearl Street Mall during a vigil calling on Hamas to release Israeli hostages.

The FBI director characterized the incident as a “targeted terror attack,” although Boulder police said it was too early in their investigation to confirm a motive.

One person, an unidentified man whom bystanders pointed out to officers, was arrested, Boulder police Chief Steve Redfearn said. Investigators are working to identify the suspect, he added.