The death toll in the Sunday's explosion at a firecracker manufacturing unit at Gokulapadu in the district has reached seven.
K Krishna (24) succumbed to burn injuries last night at Seven Hills hospital here.
The condition of two persons was critical, hospital sources said.
Assistant superintendent of police, Narsipatnam, B Satya Yesh Babu said police were yet to ascertain the cause for the explosion at the unit -- Rohit Fire Works -- but preliminary investigation revealed that one of the workers was sharpening his knife which caused sparks to fly.
The government has increased the compensation for the kin of deceased to Rs 3 lakh from Rs 2 lakh.
