A section of the beach in California was closed down for the public on Sunday (local time) after authorities discovered needles and other medical supplies had washed up onshore.
Lifeguards found a "large amount" of medical supplies around 11:30 a.m. (local time) along the beach south of the Venice Beach Pier in Los Angeles, according to the Lifeguard Division of the Los Angeles Fire Department.
"At Approx. 11:30 AM today @lacolifeguards visualized a large amount of medical supplies along the shoreline South of the #VeniceBeach Pier. The area has been cordoned off and notifications to @lapublichealth," the Department said on Twitter.
Authorities said on Twitter they did not know where the medical supplies and needles came from.
"@LACoLifeguards will continue to patrol the area by land and sea to monitor for any further materials," the Department said further.
Lifeguards said they also alerted other agencies, including the LA County Department of Public Health, US Coast Guard and police.
Venice Beach, west of Los Angeles and just south of Santa Monica, is known for its canals, trendy shops and colourful boardwalk.