The Nassau Department of Health has closed four beaches until further notice as a result of a sewage spill.

Nassau officials say a blockage in a sewer main caused untreated sewage to overflow into a storm drain and discharge into the Hempstead Harbor.

As a precaution, the county closed North Hempstead Beach Park in Port Washington, Tappen Beach in Glenwood Landing, Morgan Beach in Glen Cove and Sea Cliff Village Beach in Sea Cliff.

Officials say the beaches will be closed until the Department of Health completes a review of water quality.