An auctioneer in Honiton, Devon got a nasty shock when he opened what he thought to be a box of antiques, only to find inside a WWII German incendiary bomb. The premises were evacuated and a Royal Navy Explosive Ordnance Disposal (EOD) team was called in to dispose of the offending item.
Incendiary bombs were dropped in their thousands by the Luftwaffe during WWII, intended to cause large conflagrations which would serve the purpose of damaging property whilst simultaneously lighting up the target area for subsequent aircraft carrying more destructive high explosive bombs.
These devices were dropped in such quantities that they are still regularly found in the UK. Whilst not providing the same detonation hazard of a high explosive bomb, the magnesium in their fillings make them a potential source of contamination. This also applies to the phosphorus-filled incendiaries of WWI. It is therefore advisable to leave any such device alone.
However, because incendiary bombs were not designed to penetrate the ground, many were salvaged as souvenirs during wartime and have remained lurking in houses and garages ever since. As with any potential ordnance, this is not a safe practice.