Meaning of the Sanskrit Word: nijaghnuh

  nijaghnuh—they killed    SB 4.14.34
  nijaghnuh—struck    SB 6.9.19
  nijaghnuh—began to beat one another    SB 8.10.6
  nijaghnuh—slashed with weapons and killed    SB 8.10.35

Can't find any compound Sanskrit words containing nijaghnuh.