Police are trying to trace 24 diazepam tablets that are missing in the Edinburgh area.
The tablets were in a rucksack, which was left on a number 33 Lothian Bus this morning.
The rucksack was found with all of its other contents, except for the missing 5mg diazepam tablets.
Officers are now appealing for the tablets, which can cause significant harm, to be handed in to police.
Lothian Buses no. 33 runs between Baberton and Gorebridge/Dalkeith Campus.
Inspector Caroline MacKay said: “We are eager to recover these tablets as a matter or urgency.
“If they are taken by someone they are not prescribed to they can be very dangerous. It is essential they are recovered as quickly as possible.”
Anyone with information can contact Police Scotland on 101, or through Crimestoppers on .