Bangladesh has widened its police operation in pursuit of more people suspected of being involved in the killing of a Dhaka-based blogger, a day after the arrest of two individuals allegedly linked to the case.
Saiful Islam, police deputy commissioner, said on Friday that there were ongoing operations to go after several men, who are currently out on bail, and may be also linked to the hacking to death of Niloy Chatterjee.
"We have already found the trade of some of them. They will be arrested soon," he told Al Jazeera.
Q&A: Why are bloggers being killed in Bangladesh?
Detectives are now searching for Redwanul Azad Rana, operations chief of Ansarullah Bangla, a Muslim group which has been blamed for previous attacks on bloggers, and "cell leaders" Nabir Hossain Nabin and Abdul Kabir alias Zaber. Bounties have been issued for their arrest.
Rana has been accused of being the alleged mastermind in the killing of bloggers Ahmed Rajeeb Haider in 2013, and Avijit Roy, Washinqur Rahman Babu, and Ananta Bijoy Das this year.
Police said they would also investigate three other Ansarullah members.
On Thursday, two suspected members of the group, including one who was out on bail on a charge of attempted murder, were arrested in the killing of Chatterjee, the fourth such deadly attack this year.
Saad al-Nahin and Masud Rana were arrested by the detective branch, which has been handling the case rather than regular police, said Dhaka Metropolitan Police spokesman Muntasirul Islam.
Local media reported that Nahin was arrested in 2013 on a charge of attempted murder in an attack on blogger Asif Mohiuddin, who was injured. Nahin was freed on bail but was supposedly being watched by detectives.
Masud Rana was also accused in the case, but his name was dropped from the charge sheet.
On August 14, at least four men posing as tenants entered an apartment building and hacked to death 28-year-old Niloy.
Asha Moni, the blogger's wife, has filed a murder case against four unnamed persons.
Friends of Niloy said he had received several threats that had prompted him to remove all his photos from his blog.
The friends said Niloy had a Facebook account in which he criticised conservative religious groups at home and abroad, as well as hardline views of other religions.
Family and friends said Niloy had sought police protection after he was threatened, but officers had asked him to leave the country for his own safety.
Hours after the killing, Ansar-al-Islam, which intelligence officials believe is affiliated with al-Qaeda on the Indian subcontinent, sent an email to media organisations claiming responsibility and calling the blogger an enemy of Allah.
The authenticity of the email could not be independently confirmed.
The US has expressed its concern over the killing, while the UN called for Bangladeshi authorities to ensure accountability and prevent such violence.
Islam is Bangladesh's state religion, but the Muslim-majority country is governed by secular laws based on British common law.
Over the last decade or so, extreme interpretations of Islam have steadily gained ground.
Source: Al Jazeera and agencies