A 36-year-old man who was injured in an explosion at Nagerbazar area died at a state-run hospital in Kolkata, an official of the medical establishment said on Monday.
With this, the death count in the explosion has risen to three.
The man identified as Sharat Sethi, a washerman, was sitting at a nearby tea stall when the low-intensity blast took place on October 2 morning.
Sharat Sethi died at the RG Kar Hospital on Sunday night, the official said.
Another victim of the blast, Ajit Halder, died at the hospital on Saturday night.
West Bengal CID, which is investigating the blast, said the death of fruitseller Ajit Halder on Saturday night would slow up their probe.
"He (Halder) was giving us important information on what had happened on that day," a senior officer of the CID said.
A seven-year-old boy was killed and nine people, including his mother, were injured in the low-intensity explosion in front of a fruit stall in the northern suburb of the metropolis.
The boy's mother is undergoing treatment at the SSKM hospital, an official of the state-run facility said.