Nine beaches in Sydney, including well-known Manly beach, were closed to bathers on Tuesday after small white and grey balls of debris washed up on the shores at the height of the summer holiday season.

The discovery of the marble-sized balls comes after a similar incident in October closed Sydney's Bondi Beach, among other tourist hotspots.

Nine beaches in Sydney were closed on Tuesday as authorities investigated marble-sized balls of white and gray debris that had washed on shore.

On Tuesday, January 14, nine beaches in Sydney were closed to swimmers due to mysterious balls washing ashore. Local authorities are already trying to determine the origin of these unknown findings. Ocean beaches in Sydney,

On Tuesday, January 14, nine beaches in Sydney were closed to swimmers due to mysterious balls washing ashore. Local authorities are already working to determine the origin of these findings. Sydney's ocean beaches,

Mysterious marble-sized balls washing up on Sydney beaches baffle authorities - Northern Beaches Council says they don’t know what the balls actually are