A 31-year-old man has been arrested on suspicion of preparing a terrorist act following the discovery of non-hazardous substances in Kensington Gardens, London.

Investigation into Drone Threat

The arrest is part of an ongoing investigation into claims made by an Islamist group, Harakat Ashab al-Yamin al-Islamia (HAYI), that they were targeting the Israeli embassy with drones carrying radioactive materials. Authorities have made a total of 28 arrests related to recent incidents, with eight individuals charged with arson-related offenses.

Kensington Gardens Incident

Kensington Gardens was initially closed on April 17 after HAYI released a video purporting to show drones equipped with radioactive and cancer-causing materials. Police and forensic teams examined discarded items found in the park, including jars containing a substance that was later determined to be harmless.

Recent Arrests and Releases

The Metropolitan Police confirmed the 31-year-old man was arrested at an address in Potters Bar on Wednesday morning and remains in custody. Officers are currently conducting a search of the property. This follows the arrest of a 39-year-old man in Ealing on April 21, who was subsequently released without charge, and a 37-year-old man in Devon, who was released on bail until July.

HAYI and Previous Incidents

The Counter Terrorism Policing investigation began after HAYI released the video on April 17, which depicted individuals in hazmat suits handling drones bearing the group’s logo. Despite the video being described by security sources as amateurish, authorities took the threat seriously. HAYI has claimed responsibility for multiple incidents since the escalation of the US-Israel-Iran conflict, including arson attacks on ambulances belonging to a Jewish charity and attempted arson at a synagogue and an Iranian TV station.

Emergency Response and Security Measures

Emergency responders, including the Metropolitan Police’s CBRN team, the London Fire Brigade, and the London Ambulance Service’s hazardous area response team, were deployed to Kensington Gardens. The Metropolitan Police’s underwater search team also conducted searches near the bandstand. The Met Police confirmed the Israeli embassy was not attacked but investigated potential connections between the video and the discarded items. Counter Terrorism Policing officers are currently working with organizations to provide security advice.