The police on Wednesday arrested the owner of a semi-built plot in Delhi for alleged negligence after two workers died while cleaning a septic tank at the site the previous day, PTI reported.

The deaths took place after the workers inhaled toxic gas inside the septic tank. Three workers were hospitalised.

Rohini Deputy Commissioner of Police SD Mishra identified the owner as Gulam Mustafa. The police told the news agency that the owner and a mason had allegedly forced the workers to clean the tank despite them telling them that they were not trained for the job. The accused allegedly threatened to not pay them three days of wages if they did not follow the order.

Mishra said that the mason will be arrested soon, The Indian Express reported. “Mustafa lives in the central district, where he also runs a shop,” Mishra said. “He was renovating the house on the plot which he owns. We have been told that the other accused, Rambir, the mason, will be discharged from the hospital soon.”

Meanwhile, Chief Minister Arvind Kejriwal met the family members of the victims and promised a compensation of Rs 10 lakh to them.

The National Human Rights Commission demanded a report on the matter from the Delhi government, the police and chief secretary within six weeks. The rights panel asked the government to specify if it had issued any guidelines banning the cleaning of septic tanks and if they were adhered to. The panel also asked the government to mention how it planned to address the matter.

Leader of the Opposition Vijender Gupta accused the Delhi government of being insensitive to the plight of the sanitation workers. “The death of two workers due to inhaling poisonous gas during the cleaning of sewer in Prem Nagar area of Outer Delhi was due to the negligence of the Delhi government,” Gupta said. “These workers are from Dalit families, but their tragic death due to poisonous gas has again made it clear that the Delhi government is not serious about saving lives of manual scavengers from these accidents, their rehabilitation and improving the condition of working.”