Slain writer Avijit Roy's father, Prof Ajoy Roy, has called upon the prime minister to bring the killers of his son to book and ban all militant outfits.
The noted educationalist and former professor of physics at Dhaka University made the call when Avijit's body was taken to Aparajeyo Bangla at Dhaka University on Sunday morning.
"Try the killers of Avijit and all those who were killed in militant attacks. And ban all militant outfits, including Jamaat-e-Islami," he said.
He also called upon everyone to unite and create pressure on the government for the trial of Avijit's killers.
Prof Ajoy also termed his son's murder a sign of the government's failure.
Gonoforum President Dr Kamal Hossain said: "Had the previous killings been properly tried, this [killing of Avijit] could not have happened."
He questioned the role of the police personnel on duty around the scene of the murder.
Dr Kamal also welcomed US Federal Bureau of Investigation (FBI) for its willingness to get involved in the investigation into the murder.
Human rights activist Mahfuza Khanam said: "Free thinkers are being killed one after another. But we will not bow down before fundamentalists."
She also called for forming social resistance to avoid the recurrence of such brutal attacks.
Avijit, 45, was hacked to death and his wife Rafida Ahmed Bonya, 35, was seriously injured in an attack by unidentified assailants near the TSC roundabout on Thursday night.