"Stalk" plane over Yugoslavia, summer 1944

[Nick Beale]

Originally Posted by tegbridges

… a "Stalk" plane appeared.

If it wasn't clear from the earlier answers, what your father probably meant was a "Storch" (=Stork) the German name for the Fi 156. These planes were certainly used as spotters (and were present in Yugoslavia) but an attack with bombs and machine-guns probably came from one of the other types mentioned above.

If you had an exact date (too much to hope for, I guess!) there might even be a deciphered report of the day's operations, like this. My suspicion is that almost any group of people on the ground in the countryside could look like "partisans" to the airmen and was liable to attack.