The party, in a statement issued minutes after the verdict, announced countrywide strikes for Thursday, Sunday and Monday.
The International Crimes Tribunal-1 on Wednesday sentenced Nizami to hang until death, nearly a year after the case was wrapped up.
It has found Nizami to be criminally responsible for the execution of intellectuals and guilty of conspiring to commit war crimes.
Nizami led the Pakistan Army’s vigilante militia outfit Al-Badr to abort Bangladesh’s birth.