D ozens of girls at an Indian care home for runaways and sexual abuse victims have tested positive for coronavirus, raising renewed scrutiny over the management of state-run shelters as the country faces a surge of new infections.

The shelter in the northern Indian state of Uttar Pradesh has since been sealed, and the 57 girls who tested positive - five of whom were pregnant - were moved to hospitals, with staff put in quarantine, local officials said.

The outbreak sparked anger on social media, and opposition politicians said it reflected negligence by state authorities and a lack of care for the girls - all aged under 18, demanding a probe into how the virus reached the shelter.

"We demand the Uttar Pradesh government... take this seriously and conduct a high-level, impartial investigation so the culprits can be punished in the strictest way," Kumari Mayawati, a state opposition party leader, tweeted on Tuesday.

She also urged reform in the management of all state shelters amid expressions of concern about possible sexual abuse at the home due to the five girls' pregnancies. Cases of rape were reported at other such shelters several years ago.

The district magistrate of Kanpur district, where the home is located, said the girls were already pregnant when they were admitted last year. He said investigations were under way into their sexual assaults.

India's national human rights commission, child protection panel and the state commission for women have also demanded detailed reports on the case and proper treatment for the girls.

The case comes as India grapples with a steep rise in new coronavirus infections. The country now has more than 440,000 confirmed cases, behind only the United States, Brazil and Russia, according to Johns Hopkins University data.

More than 14,000 Indians have died from COVID-19, with stretched hospitals scrambling to accommodate patients.

Ajit Kumar, a probation officer at Kanpur's women and child development department, said the outbreak at the shelter may have come from one of the pregnant girls, who went for regular check-ups at a nearby hospital.

"The district administration is looking into the matter," he told the Thomson Reuters Foundation.

India's care homes for children came into the spotlight in 2018 after nearly 30 girls were found to have been raped and tortured in eastern Bihar state.

Weeks later, police rescued 24 girls and shut down an illegal care home in Uttar Pradesh after one former resident fled and complained about sexual exploitation. The home's owners were arrested on suspicion of trafficking the girls.

Sexual and physical abuse are common in the institutions, where many children are not orphans but are placed in care by parents who are too poor to look after them, campaigners say.

Priyanka Gandhi Vadra, general secretary of India's opposition Congress party, said such cases showed "many inhuman incidents" were happening at state-run shelters for children.

Others voiced their outrage on social media.

"Shelter home feels like more of horrific place nowadays. Hearing those crimes and happenings there. Feel sick," said one Twitter user, while many others asked who was going to take responsibility and demanded justice.