[Nick Beale]

The Daily Intelligence/Operations Summaries of Mediterranean Allied Tactical Air Forces in the UK National Archives would give you a good lead on this and then you could follow up in the Balkan Air force files (or individual squadron records if RAF units were involved).

The relevant files (from memory) would be in the sequence AIR23/6509 to AIR23/6512 but you can check that on the National Archives website.