A little-known group known as Harakat Ashab al-Yamin al-Islamiya (HAYI) has claimed responsibility for at least 17 attacks across Western Europe since emerging in March 2026, with most incidents targeting Jewish sites in London. The group has provided almost no information about its leadership or structure, but recent US court filings have intensified scrutiny over alleged links to Iran-backed militia networks. US authorities claim a senior member of the Iraqi militia Kataib Hezbollah was involved in coordinating HAYI operations, allegations that Tehran denies.
HAYI first appeared on 9 March, shortly after the outbreak of the US-Israeli war against Iran. The timing immediately raised suspicions among analysts and governments that the group could be connected to efforts by Iran or allied organizations to retaliate against Western, Israeli, or Jewish interests outside the Middle East.
Although HAYI has never publicly declared ties to Iran, several factors have fueled speculation. Its attack claims have been distributed almost exclusively through Telegram channels that support Iran-aligned Shia groups, particularly in Iraq. The group’s propaganda also incorporates visual styles and music associated with Iranian state media and Shia militias. Security analysts have additionally pointed to similarities between HAYI’s tactics and methods previously linked to Iranian proxy networks.
The strongest allegations emerged from a US Justice Department investigation. On 15 May, authorities announced the arrest of Mohammad Baqer Saad Dawood Al-Saadi, a dual Iraqi-Iranian national described as a senior member of Kataib Hezbollah. Prosecutors allege that Al-Saadi helped direct, coordinate and promote at least 20 HAYI attacks and attempted attacks in Europe and the United States on behalf of both Kataib Hezbollah and Iran’s Islamic Revolutionary Guard Corps.
According to US prosecutors, evidence recovered from Al-Saadi’s phone linked him directly to HAYI operations, including attacks in London. Investigators also claim he described the group’s activities as part of a broader campaign of “psychological warfare” designed to spread fear among civilians. The Justice Department further alleged that HAYI functioned as a front organization for larger militant networks. Al-Saadi pleaded not guilty on 1 June.
HAYI’s campaign has largely focused on property attacks rather than mass-casualty violence. Most incidents targeted synagogues, Jewish businesses and community institutions. The group’s preferred method involved arson or attempted arson using rudimentary weapons such as petrol bombs, often carried out at night when buildings were largely empty. As a result, most attacks caused limited damage and no reported fatalities.
However, the campaign escalated in April. HAYI claimed responsibility for a knife attack in London on 29 April that seriously wounded two Jewish men, marking a significant shift from attacks on property to direct violence against individuals. Earlier in the month, the group also claimed a “radioactive” drone attack on the Israeli embassy in London, though the claim was never substantiated and officials found no hazardous materials.
The organization communicates primarily through short multilingual videos released shortly after attacks. These statements often justify violence against Jewish targets and invoke the Palestinian cause. Some messages have also called on supporters in Europe and the United States to carry out attacks, including threats directed at US President Donald Trump and his family.
Little is known about HAYI’s internal structure, but arrests linked to the attacks suggest the group may rely on indirect recruitment. Authorities across Europe have detained dozens of suspects, including at least 26 people in the UK. Many were teenagers. Reports indicate that some attackers were recruited online through encrypted messaging platforms and offered money to carry out operations, often without strong ideological commitments.
The group’s last claimed attack occurred on 29 April, and it has not publicly commented on Al-Saadi’s arrest. However, the US investigation and ongoing arrests across Europe are likely to intensify efforts to determine whether HAYI is an independent organization or part of a broader Iran-aligned militant network operating beyond the Middle East.
