From Newport Police:
Oregon State Police (OSP) Hazardous Device Technicians (HDT) urge coastal visitors and residents to be aware of a potential safety hazard following a recent increase in reported findings of Marine Markers along the Oregon coast. The marking device can be dangerous and reported findings require a response by trained HDT personnel for removal.
Following reported findings during the last week, OSP and HDT, along with Air Force Explosive Ordnance Disposal personnel, encountered three Mark 25 Marine Markers along the Oregon coast. OSP and HDT personnel report that it is not uncommon to respond to one report a month after the device is found washed up on shore, but three in a week is very unusual.
Used to mark floating locations, Marine Markers are used by military aircraft over the ocean. These devices contain white phosphorous, which burns in contact with air. Devices may malfunction, but even if they do fully function there is a possibility that some white phosphorous may be remaining and could spontaneously ignite, causing serious injury.
HDT personnel urge anyone finding a Marine Marker device to not touch it, secure an area 100 feet around it and call OSP Northern Command Center at 800-452-7888.
An OSP safety bulletin with photograph on this subject is provided in the link with this news release.