Three members of the Iranian security forces were killed in clashes along the border with Iraqi Kurdistan, the Revolutionary Guards said in a statement on Wednesday.

The attack was not thought to be linked to the past week's unrest and protests.

The statement, reported by the conservative Mehr news agency, said the attack happened in the border area of Piranshahr, a region that sees sporadic clashes with Kurdish separatists based in Iraq.

Those responsible were still being pursued, the report said.