Bomb disposal experts had to be called to Norwich Castle to deal with a Second World War explosive that sparked an evacuation after it was left as a donation.

The explosive was unexpectedly left at the 900-year-old castle by a couple from the Ipswich area after they found it in their parents' garage.

A bomb disposal unit from RAF Wittering in Cambridgeshire was then called in to take it away and dispose of it safely.

Castle staff called police at 9.55am on Monday when the incendiary device was discovered and it was not known whether it was live.

Norwich Museums manager Rachel Kirk said the incident gave her staff a shock, but said strange objects being donated was not an altogether unusual occurrence.

She added: 'Apparently, a couple had been clearing out their parents' garage and came across it and then for some reason decided to bring it to us.

'It was wrapped up in cloth and just left here so it was slightly bizarre.

'They just came up here off their own backs, probably because we have the Royal Norfolk Regimental Museum here.

'Apparently they were from the Ipswich area so they could have gone to Colchester Castle, but they decided to bring it to us.'

Incendiary devices are bombs designed to start fires or destroy sensitive equipment using materials such as napalm, thermite or white phosphorous.

The explosives are not too dissimilar looking from a flare, and more commonly known as firebombs.

They were dropped on towns in the south-west of England by German Zeppelin airships in World War One and again during bombings of London in World War Two - although the origin of this incendiary device is not yet known.

Castle officials initially evacuated the museum to be extra safe but soon realised that the situation would be safe enough in a sealed area, due to the type of explosive that it was.

Ms Kirk continued: 'Once we knew what the item was we had a duty of care to protect the public because we didn't know whether it was deactivated or not.

'So on a precautionary basis and for the safety of everyone, we briefly evacuated and rang the police.

'Initially the police were not sure what to do either and needed to go above their heads, but then we were able to keep the explosive sealed off.

'The decision was made that because it was a fire bomb, rather than a bomb that would make a big bang, that we could just seal off.

'But we do get all sorts of bizarre things from time to time, lots of museums get this sort of thing.'

The museum do not yet know whether they will be able to retain the item for display as they are awaiting a report from the Ministry of Defence about the incident.

Have you got a story for the Evening News? Call reporter David Freezer on 01603 772418 or email david.freezer@archant.co.uk