Speaking to bdnews24.com on Friday, Asaduzzaman Mia said the murder may have ‘links’ to the killings of legendary writer Humayun Azad and blogger Ahmed Rajib Haider.
“Those who had come to kill (Avijit) with machetes were not outsiders. They were university-centric.”
Commissioner Mia, however, did not clarify if the police had firm leads and a specific range of suspects.
Mia said that the Detective Branch were investigating the murder. Shahbagh Police Station was also involved in the investigation.
Avijit’s father Professor Ajay Roy filed a case with Shahbagh police over the murder on Friday, accusing unnamed assailants, but alleged this was the handiwork of Islamist radicals with the backing of Jamaat-e-Islami.
But police are yet to achieve any breakthrough or arrest anyone in the case even after 36 hours.
Avijit, a bio-engineer and a naturalised US citizen, was hacked near TSC intersection at Dhaka University when he along with his wife was returning from the Amar Ekushey Book Fair Thursday night.
His wife and fellow blogger Rafida Ahmed Bonya was also seriously injured as she tried to protect Avijit.
Avijit died at the Dhaka Medical College and Hospital (DMCH) soon after he was rushed there.
Bonya was shifted to the Square Hospital in the capital from DMCH Friday.
The scene of the murder is just about 25 yards away from TSC intersection and Suhrawardy Udyan’s gate.
Police have been deployed there to secure the entrance to the book fair since it started.
The Shahbagh Police Station is only 200 yards away and police teams are guarding the access to the university round the clock.
Asaduzzaman Mia feels only someone operating out of the university could launch such a well-timed assault in a not-exactly forlorn area and escape without leaving much a trail behind.
Thursday’s attack was strikingly similar to the one on writer Humayun Azad on Feb 27, 2004.
Azad was returning home from the Amar Ekushey Book Fair when he was hacked with machetes by radical militants. He later died in Germany while undergoing treatment.
The security on the campus, Shahbagh, book fair and the surrounding areas were beefed up after Avijit’s murder, said Shahbagh police Sub-Inspector Sohel Rana.
DMP Ramna circle’s Deputy Commissioner Abdul Baten told bdnews24.com that additional police personnel have been deployed in the area.
Avijit was the founder of blog Mukto-Mona. He and Bonya had been receiving death threats for writing against communalism and those who use religion for business.
But they did not seek any security, said Shahbagh police OC Sirajul Islam.
He said their primary investigation suggested militants had carried out the attack.
An Islamist group named 'Ansar Bangla 7' in a series of tweets from its Twitter handle has described the murder of Avijit Roy as an achievement.
One such tweet described the murder as a punishment for Avijit's "crime against Islam".
The first tweet appeared around midnight on Thursday, not long after the attack.
Messages included "Allahu Akbar... A great success today here in Bangladesh."
It had also shared some photos of blood-covered body of Avijit and his wife Bonya claiming ‘victory’.
The name of Islamist blogger Farabi Shafiur Rahman, who had allegedly threatened Avijit Roy with death earlier, has resurfaced on social networking sites.
Police had arrested Farabi in connection with Ganajagaran Mancha activist and blogger Ahmed Rajib Haider’s murder on charges of incitement, but he managed to secure bail.
After filing the case in Friday morning, Ajay Roy, a former professor of physics at Dhaka University, also said extremists were behind his son’s murder and “Jamaat(-e-Islami) has backed them”.
DMP Commissioner Asaduzzaman Mia entertained similar suspicions.
“Militants have proved how desperate they could be. It occurred just near the police station! Police were at all the gates of the book fair...they (extremists) attacked in spite of that (deployment)!”
Regarding the tweets by ‘Ansar Bangla 7’, he said, “It could be a strategy to divert our investigation to a different direction. We are checking who were involved.”
Quoting flower vendor ‘Selim’, a witness, the Shahbagh police OC said two men aged between 30 and 35 carried out the attack. One of them wore a white shirt and the other a coat.
“They took one to two minutes. It was a very swift attack. When Selim shouted, they chased him. He ran away to save his own life,” the OC said.
Witnesses to the attack said they saw the attackers running away in two different directions - one towards the Suhrawardy Udyan and the other towards the Milan Chattar.
A Dhaka court has ordered police to submit the report of the investigations into the Avijit murder case on Apr 5 after the case documents were submitted.
[Additional reporting by Prokash Biswas, Shameema Binte Rahman, Kamal Talukder, Golam Mujtaba Dhruba and Faysal Atik]