Kensington Gardens in London has reopened after the discovery of several suspicious items including two jars containing a powdered substance which were deemed to be “non-hazardous”, police said.

Police in protective clothing responded to an incident near the Israeli embassy on Friday after counter-terrorism officers investigated a video shared online in which a group claimed to have targeted the embassy with drones carrying “dangerous substances”.

The video appears to have been posted by an Iran-linked Islamist group, Harakat Ashab al-Yamin al-Islamia, and depicted a target over an image of the Israeli embassy and people wearing hazmat suits flying drones, the PA news agency reported.

The Metropolitan police said on Saturday that they assessed the items found and did not identify any harmful or hazardous substances.

Commander Helen Flanagan, of Counter Terrorism Policing London, said: “We recognise this incident and consequent police activity may have caused concern among local residents and the wider public. We are grateful to them for their understanding while our work was undertaken.

“Although the items found have been assessed as being non-hazardous, we continue to investigate whether they may have any link to the online video. This work is being carried out by officers from Counter Terrorism Policing London and our inquiries remain ongoing.

“While the embassy of Israel was not attacked, we continue to work closely with the embassy and its security team to keep the site safe and secure.”

Divers from the Metropolitan police underwater and confined space search team attended near the bandstand in Kensington Gardens.

The Round Pond ornamental lake is situated just north of the bandstand and to the east of Kensington Palace in the gardens. Dogs from the London fire brigade also attended.

It comes after Harakat Ashab al-Yamin al-Islamia – which is suspected of being Iran-backed – also claimed responsibility for other arson attacks in north London.