Officials are closing multiple beaches along Delaware, Maryland and Virginia after medical waste washed up on shores.

Trash containing items like syringes began showing up along the coast of Assateague on Sunday, Sept. 15, park officials said in an announcement on Facebook.

“The Chincoteague Public Beach in the Virginia unit has been added to the Closure List,” they said in an update. “All Ocean Facing Beaches at Assateague Island National Seashore are now closed to swimming or wading due to medical waste coming ashore.”

Officials don’t yet know where the waste is coming from, but authorities plan to investigate.

The Maryland Department of Natural Resources announced that there have been no injuries as a result of the debris. Multiple government agencies are working together to ensure safety and find out when it will be OK for people to re-enter the water.

“The public is advised to take caution along the coastline, wear shoes if walking on the beach, and not touch any plastic debris in or near the water,” the department announced.

In the meantime, agencies in the area are encouraging vigilance.

“Until we are confident that the situation is under control, we recommend wearing shoes on the beach and avoiding the ocean entirely,” the Town of Ocean City said in a statement announcing their beach was added to the list of closures.

It is unclear how long these closures might be in effect, according to Assateague Island National Seashore.

“We do not know how much more material is out there, when it will stop coming ashore, and how long it will take for cleanup,” park officials said.

Overview of current closures:

— North end (all of the island North of Assateague State Park) is completely closed.

— Assateague Island State Park Beach is closed to swimming.

— Oceanside Beaches in Assateague Island National Park are closed to swimming, including North Beach, Oceanside Camping Beach, South Beach, the beach on the Oversand Vehicle Area and Chincoteague Beach.

— Ocean City Beach has closed the ocean for swimming.

— Lewes beaches, Rehoboth, Dewey, Bethany, South Bethany and Fenwick Island beaches are now closed to swimmers, according to Delaware Online.