The pre-dawn bombardment of the villages near the town of Sayed Sadiq lasted two hours, said General Jabari Yawar, a spokesman for the peshmerga, the militia which provides security in the Kurdish autonomous region of northern Iraq.

"Two civilians were wounded, livestock was killed and fields were damaged," he said.

The shelling of the villages of Kal-Daza, Jomursi, Borye, Siamio and Kani Sif started at 4:00 am (0100 GMT) and lasted until 6:00 am (0300 GMT), Yawar said.

It was the first time that the area had been shelled by the Iranian army, he added.

Other border areas have been repeatedly targeted by Iranian artillery fire as Tehran seeks to halt attacks by rebels of the Party of Free Life of Kurdistan (PJAK) operating out of rear-bases in northeastern Iraq.

At least 12 Iranian security force personnel have been reported killed in attacks by PJAK over the past fortnight.

The rebel group has close links to the Kurdistan Workers' Party (PKK), which has waged a deadly insurgency in southeastern Turkey since 1984.