Burdwan is 160 kms south of Kolkata with a population of 430,000.
A total of four people have been arrested so far in the case in which two are women.
The police investigating the blast in Burdwan, West Bengal had earlier said that video clips of Islamic fundamentalist activities were found in the cellphones seized from the blast spot.
On Sunday, two women were also arrested and remanded to police custody for two weeks in connection with the blast which left two suspected militants dead.
The CID of West Bengal police is looking into possible involvement of terror outfits like LeT and HuJI in the blast.
It is suspected that the victims of the explosion were associated with a militant outfit as a large number of watch dials, SIM cards, and other tools required to make improvised explosive devices were found in the house, police had said on Saturday.