The waterway where the deadly chemical explosive TATP was found continues to be scoured for more of the highly volatile substance.
After a member of the public last week discovered some 3kg of TATP hidden underwater near a jetty at Leschenault Estuary at Australind, a second package was discovered 36 hours later.
Both were blown up in controlled operations.
The second package was detonated by navy divers at the estuary after the first package was mistaken for drug-making chemicals and driven to police headquarters in Perth - prompting the shutdown of streets and evacuation of buildings when officers realised it was a deadly substance.
The mistake has also prompted a review of police protocols when suspicious substances are discovered.
The search for more chemicals continued over the weekend and on Monday, navy divers were assisting police with a broader search of the estuary.
A WA Police spokesman said there was no information to suggest there were more volatile objects in the area.
"Anyone intending on travelling within the estuary area is reminded to exercise caution and follow the directions of police officers at all times," he said.
Police continue to investigate who hid the chemicals in the estuary and are not ruling out the possibility they had sinister plans, including terrorism.
TATP, which can be manufactured from household ingredients and is known as "Mother of Satan", was used in the 2005 London bombings.
The discoveries last week coincided with a major gathering of foreign ministers and diplomats in Perth, the Indian Ocean Rim Association for Regional Cooperation meetings.