These bombs are neither French, Italian, Czech nor Polish.
1) According to the bombing tables published at Zemun in 1941 by the Yugoslavian high command, The Yugoslav light bombs in 1941 were:
12kg wz.27 (called in Yugoslavia "Polish 12kg bombs)
French 1kg incendiary bombs
French 10kg PA
12kg Stankovic
2) From the lists of equipments sold by Czechoslovakia to Yugoslavia in the thirties, we know that the following bombs were also in Yugoslavian service
10kg Czech bombs
Czech antisubmarine bombs 50kg and 100kg
BTW these last bombs are a mystery for me - though I found the design of Skoda hydrostatic fuze, I don't know how looked the bombs on which it was used
3) From the lists of equipment delivered by the Italians together with the SM79 we find also the following bombs:
Italian 2kg incendiary, 20kg incendiary, 100kg M/T, 250kg M/T, 500kg
Photo evidence indicates also Italian 50kg HE in this inventory
4) French
Beyond the 1kg incendiary and the 10kg PA (frag) we have a puzzling situation
a) the presence of 50kg DT2 remnant on the territory of teh formner Yugoslavai seems to be related to the use of this bomb by the Germans under the denomination SD50frz
b) A 100kg bomb appearing in a number of photos seems very similar top the late model French 100kg bomb (with annular fin reinforcement) but with some differences in its construction (separated warhead) and totally different fuze.
c) An unknown bomb which dimensions to correspond to a 200kg order of size, seems to have a lot in common with the French naval Bombe de Rupture de 150kg Model 1933, but with an annular fin reinforcement.
Any furtehr info would be very welcome