The man who authorities say firebombed a group in Boulder, Colorado, demonstrating for the release of Israeli hostages, has been charged in state court with over 100 counts, including attempted murder and assault.

Fifteen people were injured at an outdoor mall in Boulder, Colo., by a man police say attacked demonstrators with makeshift incendiary devices and a flamethrower while they were calling for the release of Israeli hostages in Gaza.

Sunday afternoon's attack in Boulder, Colorado, took place hours before the start of a major Jewish festival, Shavuot. Authorities say a man used a flamethrower and threw an incendiary device into a group holding one of its regular rallies in solidarity with Israeli hostages in Gaza.