The latest detentions were made in raids since Tuesday morning, Deputy Commissioner Masudur Rahman said.
He, however, declined to give the reasons for the arrests.
Meanwhile, on Feb 26, US-based Bangladeshi writer-blogger Avijit Roy and his wife and fellow blogger Rafida Ahmed Bonya were brutally hacked near the Amar Ekushey Book Fair.
Avijit died later and Bonya, whose condition is said to be critical, is undergoing treatment.
His family blamed extremists for the attack, which was similar to that on writer Humayun Azad in the same month back in 2004.
Farabi had allegedly posted death threats directed at Avijit, noted for his writing against religious extremism.
The chief of the Ansarullah Bangla Team had been posting inciting speeches against bloggers, according to those arrested earlier for the murder of Ahmed Rajib Haider, another outspoken blogger.
The Islamist outfit came to light when police arrested its chief Mufti Jasim Uddin Rahmani and 30 others from Barguna in August 2013.
Jihadi books, computers, laptops and CDs were later seized from Jasim’s house at Mohammadpur in Dhaka.
Police said the Ansarullah Bangla Team was out to topple the government through ‘Jihad’ by looting arms from police stations and attacking crucial establishments.