At least 30 children died since Thursday in Gorakhpur’s Baba Raghav Das Medical College amid allegations that a private contractor stopped supplying oxygen cylinders as the government-run hospital hasn’t paid dues of about Rs 70 lakh.

The Uttar Pradesh government denied the charge, saying alternative arrangements for oxygen supply were made and the patients died of “various medical reasons and illnesses”.

But according to news agency PTI, a Union home ministry statement that quoted the Gorakhpur police superintendent said 21 children died because of shortage of oxygen.

The hospital is in chief minister Yogi Adityanath’s constituency and he took stock of arrangements at the encephalitis wards two days ago during a visit.

Most deaths were reported from the neonatal and encephalitis wards.

A magisterial probe was ordered into the deaths, district magistrate Rajeev Rautela said in press conference.

“We have been told that BRD witnessed disturbance in liquid oxygen supply since last night as firm withdrew supply owing to non-payment,” he said.

“The BRD principal told us that out of an outstanding of Rs 70 lakh, Rs 35 lakh was paid to the Lucknow-based firm. But it denied receiving the money.”

The tragedy triggered outrage and the Opposition — the Samajwadi Party (SP) and Congress — sought the resignation of state health minister Siddharth Nath Singh and compensation of Rs 20 lakh to the families of each deceased kid.

“Kins of the deceased were shooed away after handing over dead bodies to them. Post mortem examinations not done on dead bodies. Admission cards were taken out of records. Extremely sad,” tweeted Akhilesh Yadav, the former chief minister and SP leader.

The Congress will send senior leader Ghulam Nabi Azad and state unit chief Raj Babbar on Saturday to assess the situation.

“Deeply pained. My thoughts are with the families of the victims. BJP govt is responsible & should punish the negligent, who caused this tragedy,” party vice president Rahul Gandhi tweeted.

Health minister Singh condoled the deaths and promised to punish anyone found guilty.

Citing a break-up of casualties since August 7, he said 60 children died of various diseases during the period in the hospital’s paediatric department but none because of shortage of oxygen.

The deaths highlight the challenges faced in India’s underfunded public health system, where successive governments have failed to address the acute shortage of staff and clinics. The problems are compounded by cases of shoddy medical treatment.

Pushpa Sales, the firm that supplies oxygen, said the hospital authorities were informed and reminded about the dues as well as the contract that promises arrears would not be more than Rs 10 lakh.

This is the second time the company has cut oxygen supply, after April last year when it owed Rs 50 lakh.

District magistrate Rautela said alternative arrangements were made from nearby nursing homes since Thursday night and from neighbouring Sant Kabir Nagar district.

“At present, there are 50 oxygen cylinders and 100 to 150 more will be reaching soon,” he added.

The BRD medical college has been recording deaths of children from mosquito-borne Japanese encephalitis and acute encephalitis syndrome for years. In the past three decades, the two diseases have claimed more than 50,000 children in eastern Uttar Pradesh, the majority in Gorakhpur district.

Chief minister Adityanath had launched a campaign to eradicate encephalitis and he is pushing to improve the state’s healthcare sector. During his visit to the medical college on Wednesday, he warned officials of strict action if any irregularity was detected in the treatment of the patients.