A medical bag was stolen from ambulance workers as they responded to a call-out, in what police described as a "despicable" act.
The theft occurred in Edinburgh's Dalry area on Saturday night.
The green rucksack with the words Emergency Medical Response contained drugs which could be harmful if misused, police said.
The bag was taken as ambulance staff attended an incident on Caledonian Road at around 9.20pm.
Police Inspector Gill Lundberg said: "Stealing from emergency service workers trying to help someone is a despicable act.
Can you help us locate a medical bag which was stolen from ambulance staff earlier. Theft occurred about 9.20pm on Sat 17/11/2018 on Caledonian Road. Any info call 101 quoting incident 4228 of 17th November. https://t.co/ABCVbUfcmcpic.twitter.com/SgyLu1aI26
— Edinburgh Police (@EdinburghPolice) November 18, 2018
"While the theft of this equipment has not impacted on the care of the patient, I am concerned what could happen if the stolen drugs were to be taken by a member of the public.
"These drugs can be dangerous if misused. I would appeal for anyone who witnessed the theft, or knows where these items are now, to contact police immediately."