Second injury is an explosion is due to -
The synopsis of forensic medicine & toxicology ;Dr k.s narayan reddy ; 28th edition ;pg.no. 138 The blast may drive multiple fragments of bomb or pieces of nearby objects, e.g gravel ,glass,wood,brick,plaster etc through the air into the skin & causes bruises ,abrasion, puncture lacerations intimately mixed on skin .
Due to flying debris
Due to blast wind
Due to shock wave
Due to complication
Mechanical injuries