Kensington Gardens in central London was closed on Friday afternoon after police launched an urgent investigation into a video claiming a drone attack on the nearby Israeli embassy.
The Metropolitan Police said it is assessing “a number of discarded items” found in the park, but stressed there is no evidence the embassy was targeted and no wider risk to the public.
Specialist chemical and forensics teams, along with police divers, remain at the scene.
The video, reportedly linked to an Iran-aligned Islamist group, appears to show drones carrying hazardous substances. Police are working to verify its authenticity and any link to the items discovered.
The embassy confirmed all staff are safe.
Conservative Party home affairs spokesman Chris Philp called on the government to outline how it is protecting the site, warning that intimidation of Jewish institutions “has no place” in Britain.
Police said they are not currently linking the incident to other alleged attacks.
