City of Mandurah rangers have closed Avalon Beach in Falcon due to a number of shark sightings.
Three bull sharks were spotted about 500 metres off the Yeedong Road boat ramp around 8.40am on Wednesday.
The Surf Life Saving helicopter has also sighted two sharks off Peron in Rockingham.
The two-metre sharks were swimming about 300 metres offshore around 10am.
Point Peron Beach has also been closed.
Beachgoers are reminded to be extra vigilant in the water.
Lake Clifton Campers air rescued after becoming stranded in wild weather
Men charged after traffic stop in West Pinjarra leads to 80kg drug seizure
Green waste fees waived for Mandurah residents after weekend storms
Concerns for missing Rockingham boy
'Prognosis terrifying' for young boy struck by car in Cooloongup
K9 Rescue's long-term resident in desperate search for loving home
West Coast Radio announcer Darragh O’Dea takes out Best Local Show at Australian Audio Awards
Lucky escape for two people after boat smashes into Mandurah Estuary Bridge
Secret Harbour Golf Links to host WA's most prestigious golf tournament