West Bengal Congress leader Manas Bhuniya said that he and state Congress president Adhir Chowdhury had gone to Pingla and met the family members of the victims of the blast.
"We have spoken to the villagers. We demand NIA probe into the blast. Our state president has also demanded an NIA probe," Bhuniya told PTI.
A team of NIA officials on Saturday met CID officers and discussed the progress of the inquiry into the blast.
Opposition Left Front, Congress and BJP have alleged that a bigger terror network was operating there and the state government was trying to hush up the matter.