The sound of worship and praise music at a Seattle, Washington church was abruptly interrupted by an arsonist who threw Molotov cocktails at the building shortly after the opening hymn.

The attack happened around 8 p.m. Thursday, Oct. 18, at the Iglesia ni Cristo church about a half-hour after the service began.   Seattle Fire Department spokeswoman Kristin Tinsley told The Seattle Times there were multiple hand-held incendiary devices used in the attack. Tinsley told the paper the improvised firebombs were lit bottles of an unknown liquid.

King5 Television reports none of the estimated 50 people who were inside the sanctuary were injured by the criminal’s actions.  The fire was put out by congregation members before the fire department arrived.

A news release issued by the Seattle, Washington Police Department says, “Seattle Police Arson/Bomb Squad detectives have taken over the investigation and are working with witnesses to develop a suspect description.

Officials have not yet determined a motive for the act of violence against the congregation.