The photos below © Igor
They were both used during ww2, but it's unknown where these were manufactered.
These two particular grenades were carried by the 17. Vzhodnobosanska divizija (17th East-Bosnian division).
The type with the round-going indent has been drawn before.
The Handgranaten-atlas, by Dietmar Schmidt-Tapkens, documented this as a Bulgarian grenade, which seems to be a mistake.
On the right you see the drawing of this grenade. SF - SN in Cyrillic on the safety cap.
*Igor came with a documented fact that SF-SN stands for " Smrt Fašizmu - Svobodo Narodu ".
This was an official salute used by the Yugoslav Partisans and means " Death for Fascists - Liberty for People ".
This saying was used during and shortly after ww2, even in paperwork.