Calcutta, Feb. 16: Suspected sewage contamination of drinking water supplied by the Calcutta Municipal Corporation to Garden Reach has made many children sick and prompted allegations that the toxic mix caused the death of a four-year-old.

At least 30 people, most of them children, have been affected by an outbreak of diarrhoea that followed the contamination of the water supplied in the Tikiapara area of Garden Reach.

Contamination has taken place in Wards 135 and 136 of the corporation.

The four-year-old Sahista Anjum died on the way to the chamber of a local doctor this evening. “My daughter was suffering from severe stomach ache. She passed away before we could take her to the doc- tor,” Anjum’s mother Niga Multan said.

Corporation officials claimed that the death had nothing to do with the contamination of water. “There has been contamination in the water line leading to diarrhoea but no death because of the outbreak has been recorded,” said Deb Dwaipayan Chattopadhyay, the chief municipal health officer.

Sources said the civic body could be disputing the cause of death because the girl died before being admitted to a hospital.

Most of the patients have been admitted to the Garden Reach State General Hospital, Paharpur Nursing home and a few other clinics. Civic authorities have opened two medical camps in the area.

The chief engineer (water supply), Bibhas Maity, said that at the time of laying sewer lines under the Calcutta Environment Improvement Project, the contractor had inadvertently caused a breach in the water supply line at Tikiapara. “The norm is for the contractor to consult us before beginning work on the sewage line. But they did not do so, leading to the breach and contamination,” said Maity.

Water supply to the area has been cut off. The corporation has sent four water tankers that have fallen well short of demand, residents said.

“The CMC water we have been getting in our taps has been visibly unhealthy — anything from yellow to black,” said Yusuf Jamal, whose daughter is among those admitted to the Garden Reach hospital.

Trinamul Congress leader Mamata Banerjee, who visited Paharpur Nursing Home, alleged lack of facilities for treating patients.

Around 150 residents put up a 15-minute roadblock on Garden Reach Road at 2.40pm and another 90-minute blockade near the route number 42 bus stand at 3pm.