Air force chiefs are trying to find out what led a practice bomb to be accidentally dropped over the UK during a fighter plane training exercise.
The 14kg bomb was lost from a Tornado GR4 aircraft during a flight from its base at RAF Lossiemouth in Moray, Scotland.
The non-explosive device fell some time during a 90-minute journey across the country.
The RAF has yet to locate the bomb and warned the public against touching it.
A Lossiemouth spokesman said: "Even if the practice bomb survived the fall, we would stress it is highly unlikely to represent a significant danger to the public.
"However, anyone who finds what they believe to be the bomb, which is approximately two and a half feet long and dark blue in colour, is advised not to touch the device but to inform the police of its location."
An investigation into the cause of the bomb's release was launched following the incident.
Practice bombs are not live devices but are made to look and feel like real bombs. Made from concrete, they contain a small fuse that gives off smoke when they hit their target.
They are used during training exercises to give pilots the experience of flying with real ammunition and to practise their aim. The RAF said around half of the 700-mile flight took place over sea.
The overland journey included a low-level route through Northumberland and north-east Scotland.
