tokens: This remained the warhead of all Soviet MANPADS up to and including most 9K38 Igla variants ; to address the problem of poor lethality , a more powerful HE filling than TNT , improved fuzing , a terminal maneuver , and finally a separate charge to set off any remaining rocket fuel were gradually introduced in later MANPADS systems , but the original Strela-2/2M warhead design of a directed-energy HE charge in a pre-fragmented casing remained .