Shark spotted metres from shore in Perth

A shark has been filmed a few metres from shore at a Perth beach, less than two days after a teenage girl was fatally attacked by a shark off the state's south coast.

The two-metre shark, of unknown species, was first reported to Surf Life Saving WA at 12.30pm on Wednesday, with a member of the public saying it was swimming around the Swanbourne and Cottesloe area.

The SLSWA was then told about 2pm the shark was "thrashing around" in the water close to Narrows Bridge.

Video taken earlier on Wednesday afternoon shows the shark close to the shoreline at Grant Street dog beach, north of Cottesloe.

SLSWA have not confirmed the sighting and beaches remain open.