Top cleric issues fatwa calling on all Muslims to avenge ‘blood of the martyr’ Khamenei prompting fears of sleeper cell and lone wolf attacks across the globe

A senior Iranian cleric has issued a fatwa calling on Muslims to avenge the ‘blood of the martyr’ Ayatollah Ali Khamenei.

Following the Supreme Leader’s death on Saturday, Iranian religious leader Nasser Makarem Shirazi issued an official religious edict claiming that all Muslims must avenge his death.

Shirazi stated:o USA and Israel These were the real perpetrators of this crime.’

A fatwa is an Islamic ruling issued by religious authorities or scholars that their followers are obliged to comply with.

Experts have warned that excessive disclosure means the world is more likely to see Iran’s sleeper cells and lone wolves carry out horrific terror attacks in a variety of locations including embassies, restaurants and shops.

Counter-terrorism expert Gaffar Hussain told the Daily Mail: ‘Iran has a long history of exporting terrorism around the world and has a history of targeting dissidents and journalists in the UK.

‘This is a very real threat that has increased since the outbreak of war and for which security services must remain vigilant.’

In recent years, Iranian agents have been accused of attempting and often succeeding in carrying out bomb and assassination plots.

In 2018, France uncovered an alleged bomb plot at a rally of Iranian dissidents in Paris attended by 100,000 Iranians and hundreds of international dignitaries. The same year, Denmark accused Iranian intelligence of trying to assassinate a dissident on its territory.

And in 2012, Indian police concluded that Iranian agents were responsible for a bomb attack that targeted an Israeli diplomat in New Delhi and injured at least four people.

Iranian religious leader Nasser Makarem Shirazi (pictured) issued an official religious edict claiming that all Muslims must avenge the Ayatollah.

After the Israeli-American bombardment of many cities in Iran on March 3, 2026, columns of smoke rose in the skies of the capital Tehran.

British intelligence agencies are currently keeping a close eye on Iranian sleeper cells for fear of reprisals for US-Israeli attacks.

Heiko Heinisch, Austria’s leading expert on Islamism, told the Daily Mail: ‘We know that the Iranian Revolutionary Guard has networks operating in Europe, consisting of embassies, consulates and mosques under the control of the Iranian regime.’

He warned that the most vulnerable targets were ‘soft’ targets, including ‘companies, restaurants or stores with links to Israel or run by Jews’.

Heinisch added that Shirazi’s fatwa is of great importance: ‘He is a well-known and respected legal scholar who was appointed to the Assembly of Experts for the establishment of the Iranian Revolution in 1979 and played a role in the preparation of the first constitution.

‘We must take the fatwa he wrote seriously. ‘The fatwa given by a Grand Ayatollah like Shirazi can be considered an instruction.’

Last year MI5 warned that Iran was behind 20 potentially deadly plots on British soil in the past 12 months.

Iran’s targets also included the Israeli embassy in London, located next to Kensington Palace and Hyde Park.

Other experts said they believe individuals who have little or no connection to the Iranian regime but still believe in its values ​​are more likely to pose a greater threat to the West.

Former Israeli security official Avner Vilan told the Mail: ‘What interests me more are the smaller-scale actions; either people who take the fatwa as inspiration or regime supporters in Europe who may interpret it as a religious sect and take matters into their own hands.

‘These may not necessarily be people working directly for Iran. They may be regime sympathizers or Shiite supporters who decide to act independently.

‘More organized operations, such as planting bombs or launching complex attacks, require coordination and resources. Right now Iran is largely on the defensive, so I doubt they have the capacity to organize something like this.

‘More likely are sporadic actions carried out by individuals or very small groups. Even a person who believes he follows a religious order can cause trouble.

‘Sometimes these actors do not even have direct connections with the regime. They can only see the fatwa, accept it at face value, and independently decide to act on it.

‘We must also remember that different extremist groups can cooperate when their interests align. Even ideologically rival organizations can work together if they have a common enemy.’

Former Israeli senior intelligence official Dr. Shmuel Bar told the Mail that organizing sleeper cell activities requires significant time and resources, making an attack from an official cell unlikely.

He said: ‘SSuch operations take longer and Iran will now want to act more directly. However, Western intelligence’s awareness of this option is quite high. The internet outage in Iran will also make direct orders more difficult.’

Heinisch added: ‘Security agencies are monitoring people with links to the Iranian regime. As far as I know, protection of Jewish, Israeli and American institutions throughout Europe has been increased.

‘The problem lies in the sleeper cells and the lone perpetrators who have so far gone unnoticed. Potential perpetrators can be found in groups that feel loyal to the regime and in radical anti-Israel circles.’

As for what the fatwa might mean for Europe and the UK, he said it was “difficult to judge”.

He said: ‘The problem now is that there are so many potential perpetrators that we can track them all on one hand. On the other hand, there are so many potential targets.

‘Obvious targets such as embassies and their staff or synagogues are under increased surveillance. But beyond that there are countless soft targets. Since October 7, 2023, we have seen that almost every recognizable Jew on the street and every Jewish business is a potential target for the anti-Israel scene, which includes supporters of the mullahs’ regime, Hezbollah and Hamas.’

The academic drew attention to the incidents of violence caused by fatwas in the past.

The most infamous of these was directed at British author Sir Salman Rushdie, who wrote ‘The Satanic Verses’ in 1989.

The infamous book drew the ire of Ayatollah Ruhollah Khomeini, who was the ruler of Iran from 1979 to 1989 and issued a fatwa against the book.

As a result, Rushdie and his colleagues who helped spread the book around the world, including translators and publishers from Italy, Japan, Norway, and Türkiye, were injured or killed by religious extremists for decades.

Sir Salman was blinded in the attack at a literary festival in New York state in 2022.

Heinisch said: ‘This shows that [Shirazi’s fatwa] ‘It may also have a long-term impact.’

He added that violence may have already taken place in response to the fatwa, pointing to the mass shooting at a bar in Austin, Texas, by a man who was wearing a sweatshirt that with the words ‘property of Allah’ on it, which the expert said ‘may have been motivated’ by the decree.