ANKARA, Turkey (AP) — A small blast at a graveyard adjacent to the grounds of a NATO military facility in western Turkey damaged the installation's perimeter walls on Thursday but caused no injuries, Turkish media reports said.

The state-run Anadolu Agency said the explosion in the city of Izmir was caused by a concussion bomb, which is designed to make a loud noise but cause minimal damage.

It was planted near the military facility's walls.

Anadolu says that an operation was underway to catch the assailant or assailants who left the bomb.

Turkey has suffered a series of bombings and other attacks by Islamic State group militants or Kurdish rebels.