(CNN)An arsonist targeted a seventh St. Louis-area church Thursday -- the latest in a series of fires set in mostly black neighborhoods in recent days.
In each case, the fire was set at an exterior door and when no one was at the facility, according to a joint statement from the St. Louis Police and Fire Departments and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
"We believe that this fire-setting activity is meant to send a message," the statement said. It didn't specify what the message was.
Advertisement - story continues below