About 40 people, including secular bloggers, academics and members of religious minorities, have been killed in attacks in the past few years.
On Friday, a Hindu monastery worker was hacked to death in Pabna district.
Nityaranjan Pande, who was in his 60s, died on the spot after several people attacked him, reports said.
Analysis: Sabir Mustafa, Editor, BBC Bengali
The police drive is sweeping up various types, not just terror suspects. Police are using lists of wanted criminals, but say the main goal is to disrupt the terror networks.
It will be several days before it becomes clear whether they have managed to arrest members of the groups carrying out the sectarian killings.
The government says home-grown militants with links to opposition parties such as the BNP and Jamaat-e-Islami are seeking to destabilise the country.
More recently, a government minister even suggested that Israeli intelligence was behind the killings, alleging that a senior BNP leader had recently met a Mossad operative in India.
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Image courtesy of AFP