Hackers affiliated with Iran shut down a small British power plant for four days.

Axar.az reports, citing The Telegraph, that the incident occurred last month alongside a series of cyberattacks on US water infrastructure that affected several states.

British officials did not identify the power plant, citing security concerns, but said the incident did not affect the wider UK power supply.

The attack was reported to the National Cyber Security Centre (NCSC), which declined to comment on the incident.

A UK government spokesman said: “The UK has a highly resilient energy system. We work closely with the energy sector to protect infrastructure and ensure the highest security standards.

The Telegraph said the attack may have been intended to demonstrate that hackers linked to Iran’s Islamic Revolutionary Guard Corps (IRGC) could gain access to UK systems and disrupt sensitive infrastructure rather than cause harm to civilians.