The NIA, probing the blast in West Bengal's Burdwan district, has arrested yet another person from Assam's Nalbari district, police said here Saturday.
The central agency, which has been conducting raids in association with Assam Police since last week, raided the house of Suburuddin Ali in Boroliapara village Friday night and arrested him.
Many incriminating documents, leaflets and books related to jihadi activities, and a large quantity of medicines, which were buried underground, were seized.
Ali is a relative of Shahnur Alom, one of the 12 main accused in the Burdwan blast.
While Shahnur is still absconding, police and the NIA have arrested his wife Sujina Begum, who was also trained in jihadi activities in West Bengal.
Assam Police has so far arrested nine people including Sujina Begum for their involvement in jihadi activities. Another couple have been picked up by police for their possible involvement with Shahnur and jihadi activities in Assam.