The Iranian government accuses the armed Kurdish parties, which have camps in neighbouring Iraq's Kurdistan region, of serving Western or Israeli interests and designates them as terrorist organisations.

Since the start of the Middle East war, and despite a ceasefire announced in April, Iran has repeatedly struck these groups, although their posts and camps had largely been evacuated.

On Monday, Iran's Revolutionary Guards said unspecified groups from "northern Iraq and acting on behalf of the US and the Zionist regime were attempting to smuggle a large shipment of American weapons and ammunition" into Iran.

Ahwan Chiako from the Party of Free Life of Kurdistan (PJAK) said claims of "seizing weapons and ammunition have absolutely nothing to do with us".

"We did not send weapons. No arms or equipment belonging to us have been seized by the Islamic regime," he said.

Amjad Hossein Panahi from the Komala party said the reports of arms shipments "are completely false and merely a pretext" for Iran to "continue its drone and missile attacks on the Kurdistan region".

An official in the Democratic Party of Iranian Kurdistan (PDKI) said "we have not sent any weapons," requesting anonymity because he is not authorised to speak to the media.

At the start of the war, media reports suggested that Iranian Kurdish groups might collaborate with the US. Tehran threatened to target "all facilities" in Iraq's Kurdistan if Kurdish militants crossed the border.

But many rebels said they hoped for an uprising in Iran prior to any intervention.

Deputy prime minister of Iraqi Kurdistan, Qubad Talabani, told AFP in March that the United States was not arming Iranian Kurdish opposition groups.

US President Donald Trump initially appeared to support a potential offensive by Kurdish groups against Iran, before backtracking.

He then said in April that the US attempted to arm Iranian protesters but accused Kurdish intermediaries of having taken the weapons.