Police are investigating after a "suspicious item" was found at Orelia Oval before a junior football game.
Officers attended the oval around 10am on Sunday after a parent from the Kwinana Knights Junior Football Club found debris on the field.
Nearby residents reported hearing a loud bang earlier in the morning.
Police seized the item for further examination.
The investigation is ongoing and anyone with information should contact Crime Stoppers on 1800 333 000.
Police issue 31,000 driving infringements in first month of new AI cameras
More than 31,000 infringements have been issued from the first month of WA's new AI fixed and trailer-mounted safety cameras.
Works underway on Rockingham and Safety Bay High School redevelopments
Construction is now underway on multimillion dollar redevelopments at Rockingham Senior High School, Rockingham Education Support Centre, and Safety Bay Senior High School.
New measles exposure sites revealed in Bunbury
New measles exposure sites in the Bunbury area have been revealed.
Dawesville man charged after allegedly leaving his elderly Great Dane to suffer painful conditions
A 43-year-old Dawesville man is due to front the Mandurah Magistrates Court next month after allegedly allowing his elderly Great Dane to suffer a range of painful medical conditions without treatment.
Good Samaritan sought by police after helping teen during robbery in Baldivis
Rockingham Detectives are trying to find a good Samaritan who intervened during a robbery in Baldivis.
Under-16s social media ban now in force
Australian children under the age of 16 are now locked out of their social media accounts, as a world-first ban came into effect overnight.
Desperate search continues for missing Bunbury FIFO worker
Serious welfare concerns are held for a missing Bunbury FIFO worker who has not been seen in over four days.
Passengers now able to use credit, debit cards to tag on and off WA's public transport
WA public transport passengers are now able to tag on and off with their credit or debit cards, along with digital wallets on their mobile phones and smart watches instead of using a SmartRider.
New floating jetty speeds up emergency response times for Marine Rescue Mandurah
Marine Rescue Mandurah volunteers are heading into the busy summer boating season with a major upgrade to their operations with the installation of a new purpose-built floating jetty.