Bomb disposal experts were called to a Humberside beach after beach cleaners discovered ordnance.
Volunteers helping with the Plastic Free Hornsea beach clean at Mappleton alerted HM Coastguard Hornsea at 10am on Sunday after sightings both to the north and the south of Mappleton.
The Humber Coastguard Operations Centre were informed and team members attended both sites to assess the objects.
Pictures and grid references were taken and sent to Humber Coastguard and the 11 Explosive Ordnance Disposal (EOD) Regiment.
The items south of Mappleton were found to be within the range of the disused RAF Cowden, which ceased operation as an air range in 1998.
The EOD Regiment are heading to the scene to dispose of the items.
A larger object was found north of Mappleton, but due to an incoming tide the team had to leave the beach for safety reasons.
They will start searching again at the next outgoing tide, HM Coastguard Hornsea said.
A spokesman said: "The beach cleaners did the right thing by notifying HM Coastguard and not touching the items."
Responding on Facebook to one woman who was concerned about going to the beach, a spokesman added: "The beach is perfectly safe.
"However these things can be a regular find due to some disused RAF ranges being in the area.
"All we ask is that if people do see objects that could possibly be ordnance is that they do not touch or move them and call the Coastguard on 999.
"A team will attend and work with our partner agencies to assess remove the items."