The Egyptian man accused of carrying out an antisemitic attack in Boulder, Colorado is set to appear in federal court on Friday — a day after he was charged with 28 counts of attempted murder in connection to a firebombing that has sparked widespread fear across the Jewish community.

The FBI is investigating the attack as “an act of terrorism,” the agency said. It happened at a weekly walk in support of the Israeli hostages held by Hamas in Gaza. Among the victims is a Holocaust survivor, according to a person who knows the victim and was at the event. It is unclear what their condition is.

Hundreds of people have gathered at the local Jewish Community Center for a vigil to support the victims of the firebombing attack in Boulder