An explosive device detonated in the courtyard of a primary school in the town of Agrinio, western Greece, late on Tuesday. No injuries or damage have been reported.
Local residents who heard the blast shortly before 11 p.m alerted the police.
Police officers discovered remnants of a homemade explosive device consisting of two 1,000 ml plastic bottles filled with flammable liquid, bound together with duct tape.
The remnants of the device are currently being analyzed to gather evidence that could lead to the identification of the perpetrators.
Authorities are examining surveillance footage from security cameras in the area, local agrinionnews.gr reported.