The Kamrup Chief Judicial Magistrate remanded the six to judicial custody even though the police had wanted their custody for another seven days.
On October 11, the six accused, after their arrest the day before, had been remanded to 14 days police custody.
The six are the father-son duo of Shiraj Ali Khan and Shaikhul Islam, Rafikul Islam, Jahuruddin, Golam Osmani and Sarbesh Ali--all residents of different villages of Barpeta district.
Shaikhul Islam, alias Abdulla, is an important member of the module operating in Assam and an associate of Shakil Ahmed alias Shamin, a suspected JMB activist who was killed in the blast at Khagragarh locality of Burdwan along with another.
Shaikhul had been trained in 'jehad' at a madrasa at Simulia in Burdwan district and another one in Murshidabad district, the spokesman claimed.
Deceased Shakil Ahmed, who had visited Barpeta on several occasions under the cover of doing garment business for motivating the youths for terrorism, he added.