At least one sewer worker is killed every five days in India while digging up human feces and cleaning septic tanks without any protection, according to government data obtained by local media.

With reports of people diving into sewers with no equipment whatsoever to protect them from the toxic tanks, some 123 people are believed to have died since January 2017 while carrying out the hazardous practice. Activists have branded it one of the “most hideous forms of caste discrimination in India,” the Indian Express reports.

However, the National Commission for Safai Karamacharis (NCSK), a non-statutory body of the Ministry of Social Justice and Empowerment, says that figure is likely to be just the tip of the iceberg as data was collected on figures obtained from English and Indian newspapers – and from only 13 out of 28 local governments.

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Up to five people were killed last week in one incident alone in the capital of Delhi. A picture of a boy crying beside his dad’s body after he was killed cleaning a sewer has recently prompted a wave of anger online and the donation of $70,000 to the family.

The spate of deaths has sparked outrage among the public and prompted calls for protest. The government has ruled manual scavenging unlawful, but a lack of implementation of the order by enforcement agencies means the practice profession is still widespread, according to the Hindustan Times.

The boy walked up to his father's body at a crematorium, moved the sheet from the face, held the cheeks with both hands, just said 'papa' & began sobbing.The man was yet another poor labourer who died in a Delhi sewer on Friday. Family did not have money even for cremating him. pic.twitter.com/4nOWD9Aial — Shiv Sunny (@shivsunny) September 17, 2018

The Safai Karamchari Andolan (SKA), a campaign group dedicated to the eradication of scavenging, has called on the public to rally against the practice on September 25.

Meanwhile, authorities in Delhi are expected to convene a day before that to address the issue.