This is the Yugoslavian PROM-1, a High-Explosive-Fragmentation (HE-Frag), pressure or tripwire (TPW) actuated, bounding, Anti-Personnel (AP), landmine.
It consists of a cylindrical body with a pronged fuze inserted into the top of the landmine. The landmine is triggered by the tilting of the prongs situated on top of the landmine. This is caused by either direct pressure on the prongs or by tension on a TPW attached to them. This releases the spring-loaded striker, which is flipped downwards into the percussion cap and fires the propellant-charge.
The explosion of the propellant-charge forces the upper half of the landmine body out of the ground and up into the air, shearing off several brass screws and leaving the base plug of the landmine behind in the ground. The landmine’s body is tethered to its base by a short length of wire, which unwinds behind it as it rises.