Surfers have been rescued from the water near Rottnest Island after a 2.5 metre shark was spotted 200 metres from shore.
A witness claimed around ten surfers were pulled out the ocean onto two nearby boats that immediately came to their aid after hearing the shark alarm sound.
"The two good samaritan boaties came over from Thomson Bay area and then the surfers jumped on board the two boats... it all happened within minutes with the helicopter circling above," the witness said.
Surf Life Saving WA confirmed there was an unknown species of shark sighted near Thomson Bay around 2pm on Wednesday by helicopter.
SLS Lifesavers report unknown sp. shark sighted 13:55hrs 28/12, Thomson Bay, Rottnest Island 200m offshore
— Surf Life Saving WA (@SLSWA) December 28, 2016
The incident follows a snorkler reporting on Wednesday they were bitten by an unknown species of shark near Ningaloo on Christmas Eve.
Fisheries advise Shark incident. Snorkeler bitten diving near southern dive mooring at Bundegi sanctuary zone on 24 Dec 2016 Reported 28 Dec
— Surf Life Saving WA (@SLSWA) December 28, 2016