"We have got reports that three dengue patients have died while another 600 are affected in the state," Bhattacharya told reporters here.
Unofficial reports have however, claimed that more than 20 people have died due to dengue.
The minister said all hospitals and municipalities have been alerted over the outbreak of the disease.
Apart from Kolkata, other districts hit by the vector-borne disease are North and South 24 Parganas, Howrah and Nadia.
MLA Nirmal Majhi, who is also chairman of the Assembly Standing Committee on Health, claimed that the previous Left Front government had misutlisied funds to the tune of Rs 4,000 crore.
"There should be a CID enquiry on this," he said.
