Iran recently shot down an unknown surveillance drone on its western border, the state news agency said on Saturday.
"After spotting the drone, our air defence system missiles shot it down," Farzad Fereidooni, commander of Anti-aircraft system in Kermanshah province was quoted as saying by IRNA.
"We have given warning to 12 unknown flights last year and they have left Iran's air space."
He did not mention which country the shot-down drone belonged to. Iran has brought down U.S. surveillance and what it claims to be Israeli drones in recent years.