A brooch dating from the late Roman period and a ring said to be from medieval times have been stolen from a train.
Police said the items, valued at £1,000 and £500, were taken from an Edinburgh-bound service travelling from Durham.
The rare jewellery was left in a red plastic bag in the overhead locker by a passenger who disembarked at Durham.
However, the items were not handed into lost property and are now presumed stolen, said British Transport Police.
The medieval ring, which was left with the brooch in a red plastic Aldi bag, has the inscription "o mi hart is yovrs" (oh my heart is yours) on its inside.
The passenger who left the items was travelling from London to Durham on an Edinburgh-bound service.
The jewellery is thought to have been taken sometime between the evening of 4 October and 12.30 on Saturday 5 October.
Anyone with information is asked to contact the British Transport Police.