Sydney’s Manly Beach and nearby beaches were closed on Tuesday after marble-sized white and gray debris washed ashore.

Authorities are investigating the debris, similar to substances found on Bondi Beach in October, which were later identified as decomposed cooking oils, hair, and food waste.

The Northern Beaches Council is coordinating with New South Wales’ Environmental Protection Agency to safely remove and test the material, NBC News has reported.

Beach closures, affecting popular spots like Dee Why and North Narrabeen, come during peak summer, with officials advising the public not to touch the debris.

Written by B.C. Begley