Local police station OC Babul Akter claimed two of them were activists of the banned militant outfit, Jamaat'ul Mujahideen Bangladesh (JMB), while the other belonged to the Jamaat-e-Islami’s student wing.
They are Khalilur Rahman, Babul Hossain and Jahangir Hossain.
Rahman is suspected to have been involved in the serial blasts triggered across Bangladesh on Aug 17, 2005.
On Sunday, assailants slit the throat of 50-year-old Jagneshwar Roy, who headed the Santo Gaurio temple, after hacking him with sharp weapons.
Witnesses said three men, armed with sharp weapons and firearms, had taken part in the killing and opened fire and hurled bombs as they fled on a motorbike.
“JMB activists Khalilur (Rahman), Babul (Hossain) and Shibir leader Jahangir (Hossain) were held during raids in different parts of the district,” said OC Akter.
The victim’s family have filed a case over the murder, while police filed another under the firearms and explosives Act.
Radical outfit Islamic State is said to have claimed responsibility for the murder.
It made the claim in a statement issued through the Telegram messaging app and Twitter, Reuters reported.
It had earlier claimed credit for the murders of foreigners and the Old Dhaka bombings on a Shia community function, international media reported, quoting an intelligence group.
Bangladesh authorities, however, have dismissed the claim, saying the Middle-East-based group had no presence in the country.
Law-enforcers and investigators hold militant outfits like the JMB or the Ansarullah Bangla Team responsible for the crimes.
