A Metropolitan police spokesman said officers had completed their searches of all four properties today and no hazardous materials had been found.
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A woman involved in a car crash had to be taken to hospital by helicopter with serious injuries.
Search for missing seven-year-old underway after he was reportedly abandoned in a forest by his parents as "punishment" for throwing rocks.
Shooting of a 400-pound gorilla who grabbed a four-year-old boy after he entered his enclosure sparks public outrage and prompts petition.