Forces from the Intelligence Ministry "have identified and arrested 111 monarchist cells across 26 provinces before they could take action on the last Wednesday of the year," the ministry said in a statement carried by Fars news agency.

It was not immediately clear how many individuals were involved in the alleged cells.

The ministry said four suspected spies linked to the United States were arrested in Hamedan city and West Azerbaijan province, both in the country's west.

Authorities also arrested another 21 people accused of cooperating with the London-based broadcaster Iran International, which is outlawed in Iran, it added.

They also said they had seized firearms, bladed weapons, stun guns and batons.

The arrests come with Iran at war with Israel and the United States since February 28, when Israeli-US strikes killed the country's supreme leader Ayatollah Ali Khamenei, triggering a war that has spread across the Middle East.

Authorities have in recent weeks carried out sweeping raids across Iran, arresting in the last few days hundreds of people suspected of cooperating with Israel and the United States, local media reported.

On Sunday, police chief Ahmad-Reza Radan said a total of 500 people were arrested on suspicion of being spies and "sending information to the enemy and anti-Iranian media," according to local media.

Iran has designated Iran International a terrorist organisation since 2022 and has warned that cooperation with the channel is punishable under Iranian law.