In my opinion the two photos posted by Milan Nepali Josheph concern Vespidae, not Crabronidae. The first one seems to illustrate a specimen of the genus Vespa. Regards.
I agree with you Rinaldo, those pictures from Milan seem to be Vespidae specimens. I am thinking the pictures that I uploaded are from the Pison genus, they are very similiar to what I found on Google.
Thank you very much Dr. Antropov. I can take some detailed photos of the head from the front and the propodeum from above and send them to you (or upload them here, as you prefer) if you could please help me in the determination of the species