An Iranian semi-official news agency says an attack near the country's western border with Iraq has killed three Iranian border guards.
The Fars news agency today quoted security official Shahriar Heidari as saying the troops were killed last night while patrolling along the border in western Kermanshah province. A border outpost commander was among those killed.
Heidari says an unspecified "terrorist group" was behind the attack. No other details were immediately available.
Iran has boosted border security amid the blitz offensive in neighbouring Iraq by Sunni militants from the al-Qaeda breakaway Islamic State of Iraq and the Levant.
The militants have snatched much of northern and western Iraq from Baghdad's control.
In the past, sporadic clashes have taken place between Iranian troops and opposition groups in western Iran.
