The NIA has arrested Habibur Rehman Sheikh, wanted in the 2014 Burdwan blast case, from the Dodabalpur area of the Karnataka capital.
The official said the agency has sought help of the bomb disposal squad of Bengaluru Police to defuse the IEDs.
The official said the accused has also revealed his involvement in several instances of robberies committed in Bengaluru in 2018 in order to raise the fund for the activities of JMB.
According to NIA officials, Sheikh was a close associate of senior JMB leader Jahidul Islam alias Kausar and was associated with other JMB leaders such as Rahamatullah Sheikh and Moulana Yusuf.
He was named in a chargesheet filed by the NIA in the case in March, 2015 for his direct involvement in the conspiracy of the JMB to wage war against governments of India and Bangladesh.
The official said that Sheikh was an active member of JMB's Bolpur module in West Bengal and had attended a number of training camps conducted by the JMB.
At least two persons died and another was injured in a bomb explosion at a house in the Khagragarh locality of Burdwan on October 2, 2014.
The Bangladesh government banned the JMB in 2005, while India banned it in May this year.
On Tuesday, the JMB operative was produced before the NIA Special Judge in Bengaluru, which has granted five days' transit remand for producing him before the Special NIA Court in Kolkata.
( With inputs from IANS )