Human rights commission issued notices to Delhi chief secretary and police commissioner. (File)

The National Human Rights Commission or NHRC has issued a notice to the Delhi government and city police commissioner over the death of two labourers while cleaning a septic tank at an under-construction house in Delhi.

On Tuesday, two contractual workers died and three others were hospitalised after apparently inhaling toxic gas when they were cleaning the septic tank in northwest Delhi's Rohini.

Due to negligence by authorities, a large number of people are dying every year in such painful incidents, the NHRC said in a statement issued on Thursday.

The rights panel said it has taken "suo motu cognisance of media reports that two labourers, died while three others are battling for life after they entered an unauthorised 10-foot-deep septic tank at an under-construction house in Prem Nagar, Rohini, Delhi, on May 7".

In spite of specific laws and guidelines, such incidents are happening, the commission said.

The NHRC said it has condemned as "uncivilised" the attitude of some people who gathered at the place of incident, but did not come forward to help the victims, terming them "untouchables".

The commission has issued notices to the Delhi chief secretary and police commissioner, seeking a detailed report within six weeks.

It has also asked the Delhi government to inform whether it had issued any guidelines prohibiting unauthorised construction and cleaning of septic tanks, and, if so, why its strict compliance is not being ensured.

The NHRC said, "It has directed the Delhi government to chalk out appropriate instructions to deal with the issue and inform."

The incident took place at a semi-built plot owned by Gulam Mustafa in Rohini's Bhagya Vihar area, according to police.

He had started construction of a house a few days ago.

Mustafa and a mason, named Rambir, had allegedly asked the two labourers to clean the tank, but they refused as they were not trained, police had said.

However, they were blackmailed that they would not get paid three days of wages and were forced to enter the tank, a senior police official had said on Tuesday.

The commission has observed that apparently there were multiple reasons which might have caused the death of the two persons.

Had the septic tank not been constructed in an unauthorised manner and had the labourers been not forced to go inside the septic tank without any safety gear or prior training, two precious lives could have been saved, it said.

"The victims were rushed to the Sanjay Gandhi Hospital where Deepak and Ganesh were declared brought dead while three others were said to be critical.Locals have also reportedly, alleged that when the victims were pulled out of the tank, they were breathing but no one touched them saying they were untouchables," the NHRC statement said.

Mustafa was arrested on Wednesday.

Delhi Chief Minister Arvind Kejriwal has met the family members of the victims and promised a compensation of Rs 10 lakh to the family of those who died.