Three free thinkers have been hacked to death in less than three months while police are yet to arrest the real culprits behind the grisly attacks.

Cops have repeatedly claimed that militant outfits, specifically Ansarullah Bangla Team, had links with the killing of Avijit Roy and Oyasiqur Rahman.

They could neither come up with any concrete evidence nor arrest the real culprits in connection with the killings. They only arrested Oyasiqur's killers, who were caught by public.Against the backdrop, different rights and socio-political bodies yesterday condemned the government's failure to arrest the killers, saying it could have saved the life of Ananta Bijoy Das.

The failure of the police to arrest the killers sparked a wave of outrage from all quarters, including the social media platforms.

On Monday, Ananta wrote in his Facebook page: "When Avijit was killed, police watched from nearby. The killers escaped safely. Later, police claimed they had no negligence in duty. I want to know what their duty is!"

Prof Ajoy Roy, father of slain blogger-writer Avijit Roy, called into question the efficiency of the police since the killings of the three bloggers took place within a short period of time.

"They have been killing free thinkers one after another while police and detectives are doing nothing," said the father whose son was hacked to death on February 26.

Prof Ajoy went to the office of the Detective Branch (DB) of police on Minto Road couple of days ago to know about the progress of Avijit murder case but detectives did not tell him anything hopeful, he said.

"They [detectives] said they were investigating and would not disclose information for the sake of investigation," he said, adding that he believed that the Bangladesh police were capable of arresting any killer anytime.

Meanwhile, Oyasiqur's father Tipu Sultan said he was completely unaware of any progress into his son's murder case. He also said no cops had contacted him since his son was killed in March.

Tipu said he left the area [Tejgaon] where he and his son spent last 19 years together.

"Nothing will console me now. I don't know what fault I have committed for which Allah punished me in such a way," he said.

Condemning the killings, rights body Ain o Salish Kendra in a statement yesterday said the government should take effective and cautious steps to ensure security of all bloggers and progressive-minded individuals.

"The repeat of such incidents [killing] proves that no step was taken by the government to provide security of the individuals who are in life threat," reads the statement.

Anti-war crimes platforms Ekattorer Ghatak Dalal Nirmul Committee in another statement said Ananta was killed in a way similar to the ones in which bigots killed free thinkers Ahmed Rajib Haider, Avijit Roy and Oyasiqur Rahman.

"If proper investigation, justice and exemplary punishment had been ensured to the earlier killings, we might not have seen the similar kind of killing," reads the statement.

Ganatantrik Bam Morcha also condemned the killings of the free thinkers.