People are being warned of the dangers of handling suspicious devices that are washed up on the Humber coastline.
The bomb and buoy were both caught up in trawler fishing nets
The Royal Navy issued the warning after the recent discoveries of an unexploded World War II bomb and an old sonar buoy in waters off the Humber Estuary.
Lt Cdr Charles Wood said there were still a lot of items left in the North Sea that contained pyrotechnics.
"If you discover something and you aren't sure then be safe, don't touch it, and inform the police," he said.
"Not all objects are bright shiny metal. After being in the sea they are often rusty or covered in crustaceans, which can give them a rock-like appearance."
The World War II bomb discovered off Flanborough Head last week was detonated in a controlled underwater explosion.
Earlier this week, Bridlington harbour was closed for several hours after a suspected bomb was caught in a trawler's fishing nets.
Controlled explosions were carried out and experts later said they believed the device to be an abandoned sonar buoy.