The toll due to the consumption of spurious liquor in Tamil Nadu climbed to 20 on Tuesday, ANI reported, citing the police.

Thirteen residents hailing from the Ekkiyarkuppam village in Viluppuram and seven from Chengalpattu’s Madhuranthagam have died, the news agency reported. Forty-five residents are still undergoing treatment.

The authorities are yet to find a connection between the deaths in the two districts but are investigating the possibility of such a link. Preliminary investigations showed that those who died may have consumed spurious liquor mixed with ethanol and methanol, Inspector General of Police (North) N Kannan said.

On Tuesday, the police said in a statement that the residents died after consuming methanol, a flammable chemical compound used as a fuel alternative, not illicit liquor.

“Due to the effective measures taken to prevent the brewing of illicit liquor in Tamil Nadu, and also the enhanced vigil to curtail the movement of the illicit liquor, resulted in its non-availability in the state,” Director General of Police C Sylendra Babu said in a statement. “Few persons resorted to selling the chemical substance stolen from industrial units. Hence, this tragedy.”

Babu added that the police were trying to ascertain as to which industrial unit the methanol was stolen from.

The police have so far arrested eight persons in connection with the deaths, reported The Times of India.

Meanwhile, the National Human Rights Commission has sought a report from the police on the deaths.

“It [the report] should include the status of the FIR registered by the police, medical treatment of the victims and compensation if any, granted to the aggrieved families,” the commission said. “The Commission would also like to know about the action taken against the delinquent officers, responsible for the tragedy.”

Chief Minister MK Stalin has transferred the case to Crime Branch-Criminal Investigation Department and assured people that stringent action will be taken against the culprits. Stalin has also announced that the families of those who died will be paid Rs 10 lakh. Those who have been hospitalised will be paid Rs 50,000 each.