Bathers have been warned of a possible increase in the number of sharks at False Bay beaches on Thursday because of high fish activity, the City of Cape Town said.
Large schools of yellowtail fish had been spotted along the coastline in the morning, which could attract sharks, disaster risk management spokesman Wilfred Solomons-Johannes said.
Red flags, which indicated a high shark alert, had been raised at all beaches in the bay. Bathers were advised to be vigilant, obey the shark siren, and take note of a change in flags.
Shark spotters were watching the coastline.