A group of about 100 migrants heading home from Delhi was hosed down with a disinfectant solution in Bareilly town on Sunday, attracting wide condemnation and an admission from local authorities that they had gone too far.

Videos show migrant workers and their families, including women and children, who had arrived on a bus from Delhi squatting at Bareilly’s Satellite bus station while men in protective suits hose them down.

Someone is heard telling them to shut their eyes as the spraying begins. Several people in the group complained of a burning sensation in the eyes.

The disinfectant, a sodium hypochlorite solution, is often used to keep swimming pools sanitised.

As a row erupted with Priyanka Gandhi Vadra, Akhilesh Yadav and Mayawati condemning the action, district magistrate Nitish Kumar blamed “overzealous” personnel and said action was being taken against them.

Kumar said teams made up of civic and fire brigade personnel had been asked to sanitise the bus in which the migrants had arrived but they “went overboard”.

He added that some of those “affected” had been seen by the chief medical officer.

R.N. Singh, a Gorakhpur-based doctor, said sodium hypochlorite can be used to clean wounds in low concentrations but there was no evidence it could kill the coronavirus.

“Used in concentrations above 35 per cent, it can be harmful to humans. If ingested, it can cause metabolic acidosis,” he said.

“I have not seen such a method of sanitisation (by spraying humans with the chemical) in my 72 years of life.”

Bareilly’s chief fire officer, Chandra Mohan Sharma, said he was conducting a probe on the government’s orders.

“My primary probe suggests that some people, who were waiting for buses, were sitting on the road while fogging was going on. We didn’t intentionally spray them with chemicals.”

Told that videos showed the people being asked to close their eyes and mouths, Sharma merely said: “I have seen the video and am conducting a probe.”

Sources said the migrants were waiting to catch another bus home to their villages in eastern Uttar Pradesh and Bihar. Although the Centre had on Sunday ordered the states to prevent any movement of people, buses carrying returning migrants were seen plying in Uttar Pradesh even on Monday.

Priyanka, Congress general secretary, asked the state government not to do something this “inhuman”.

“The labourers have already suffered a lot. Don’t bathe them in chemicals like this. This will not protect them but will create more problems for their health,” she tweeted in Hindi.

Akhilesh, Samajwadi Party president, asked whether the World Health Organization had directed such hosing of humans.

“What arrangements were there for people to change out of their wet clothes? What alternatives are being provided for the food that got wet owing to the spraying?” he tweeted.

Mayawati called the Bareilly team’s action “inhuman and brutal” and asked the government to act.

“It would have been better if the borders of the state were sealed and two or three special trains run for labourers so that they could reach home,” she tweeted.

In Lucknow, additional chief secretary (information) Awanish Awasthi said “taking a bath in sanitisers” was allowed internationally “as long as people closed their eyes”.

But the procedure followed in Bareilly was wrong, he said, without explaining.

Awasthi said those responsible would be punished but claimed that none of those sprayed felt any adverse effects.

A home department official in Lucknow said the Bareilly authorities may have been so zealous about disinfecting the town because a resident of its Subhasnagar area had tested positive for Covid-19 on Sunday.

Following this a team from the civic body, health department, fire brigade and the police had “sealed the entire locality”.

The administration in neighbouring Pilibhit said 35 people who had returned from Saudi Arabia on March 18 had been advised “self-quarantine” at Mumbai airport but had nevertheless boarded a train to Bareilly. They had arrived in Pilibhit on March 20 by various means of transport.

Pilibhit district magistrate Vaidhav Krishna said cases had been registered against them for endangering others’ health and they had been quarantined in hospital. Their contacts are being identified and screened.