fragmentation grenade 
(also fragmentation bomb)
noun
A grenade (or bomb) designed to break into small fragments as it explodes.Historically, the most important hand grenade is the fragmentation grenade....
- Soldiers concentrated their weapons on the opening until the clearing team stacked outside it, pitched in a fragmentation grenade and rushed inside after the blast.
- It now appears, however, that, while on patrol, he had stepped on an unexploded fragmentation grenade dropped by US forces in the area the day before.