Three tiger sharks between 2.5m and 3.5m have been spotted by the Westpac Rescue Helicopter this morning.
A 3m shark was seen first about 100m offshore at Peasholm Street dog beach, causing City Beach lifeguards to close the area between the beach entrance and Floreat drain soon after.
Another 2.5m tiger shark was then spotted at Burns Beach also 100m offshore tracking north.
The third 3.5m shark, and biggest of the three, was then seen 250m offshore of Alkimos Reef tracking west.
No other areas have been closed so far.