Iran arrested five people accused of links to the Israeli spy agency Mossad, state media said on Thursday, in the second such report in as many days. 

"A spy network consisting of five members affiliated with the Zionist regime was identified and arrested," said a police intelligence statement quoted by the official news agency IRNA.

The network had been in contact with a middleman from Mossad "with encouragement from the head of a separatist group", it said, without giving further details.

On Wednesday, Iran's intelligence ministry said agents linked to Mossad who were arrested last week were also members of Komalah, a Marxist group which seeks autonomy for Kurdish-populated areas of northern Iran.

They were alleged to have been planning to target "sensitive sites" in the Islamic republic, it said.

Iran and arch-foe Israel have been engaged in a years-long shadow war.

Tehran has accused Israel of sabotage against its nuclear sites and assassinations of key figures, including scientists.